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1.  Roll-your-own tobacco use among Canadian youth: is it a bigger problem than we think? 
BMC Public Health  2012;12:557.
Despite the apparent decline in the popularity of roll-your-own (RYO) cigarettes over the past few decades, RYO tobacco products are widely available and used by a substantial number of adult smokers. Considering research has yet to examine the prevalence of RYO tobacco use among youth populations, this manuscript examines the prevalence of RYO tobacco use and factors associated with RYO use in a nationally representative sample of youth smokers from Canada.
This study used data collected from 3,630 current smokers in grades 9 to 12 as part of the 2008-09 Canadian Youth Smoking Survey (YSS). Descriptive analyses of the sample demographic characteristics, smoking status, cigarettes per day, weekly spending money, and frequency of marijuana use were examined by RYO tobacco ever use and RYO tobacco current use. Two logistic regression models were used to examine factors associated with RYO tobacco ever use and RYO tobacco current use.
We identified that 51.2% of current smokers were RYO ever users and 24.2% were RYO current users. The prevalence of RYO current users was highest in Atlantic Canada (40.1%) and lowest in Quebec (12.3%). RYO current users were more likely to be male (OR 1.27), to be daily smokers (OR 1.75), to use marijuana once a month or more (OR 2.74), and to smoke 11 or more cigarettes per day (OR 6.52). RYO current users were less likely to be in grade 11 (OR 0.65) or grade 12 (OR 0.40) and less likely to have between $20 to $100 (OR 0.44) or more than $100 (OR 0.45) of disposable income.
Developing a better understanding of RYO tobacco use among youth is important for advancing population-level tobacco control prevention strategies and cessation programs. We identified that RYO tobacco use is not a negligible problem among Canadian youth. Ongoing research is needed to continue monitoring the prevalence of RYO use among youth and the factors associated with its use, but to also monitor if this more affordable tobacco product is being targeted to price sensitive youth smokers.
PMCID: PMC3434020  PMID: 22834563
Roll-your-own tobacco; Disposable income; Youth; Drug use; Smoking
2.  "It's at a Time in Your Life When You Are Most Vulnerable": A Qualitative Exploration of the Financial Impact of a Cancer Diagnosis and Implications for Financial Protection in Health 
PLoS ONE  2013;8(11):e77549.
Although cancer patients may incur a wide range of cancer-related out-of-pocket costs and experience reduced income, the consequences of this financial burden are poorly understood. We investigated: financial adjustments needed to cope with the cancer-related financial burden; financial distress (defined as a reaction to the state of personal finances); and factors that increase risk of financial difficulties. Two sets of semi-structured face-to-face interviews were conducted with 20 patients with breast, lung and prostate cancer and 21 hospital-based oncology social workers (OSWs) in Ireland, which has a mixed public-private healthcare system. Participants were asked about: strategies to cope with the cancer-related financial burden; the impact of the financial burden on the family budget, other aspects of daily life, and wellbeing. OSWs were also asked about patient groups they thought were more likely to experience financial difficulties. The two interview sets were analysed separately using a thematic approach. Financial adjustments included: using savings; borrowing money; relying on family and friends for direct and indirect financial help; and cutting back on household spending. Financial distress was common. Financial difficulties were more likely for patients who were older or younger, working at diagnosis, lacked social support, had dependent children, had low income or had few savings. These issues often interacted with one another. As has been seen in predominantly publically and predominantly privately-funded healthcare settings, a complex mixed public-private healthcare system does not always provide adequate financial protection post-cancer. Our findings highlight the need for a broader set of metrics to measure the financial impact of cancer (and to assess financial protection in health more generally); these should include: out-of-pocket direct medical and non-medical costs; changes in income; financial adjustments (including financial coping strategies and household consumption patterns); and financial distress. In the interim, cancer patients require financial information and advice intermittently post diagnosis.
PMCID: PMC3823871  PMID: 24244279
3.  Are Lower Response Rates Hazardous to Your Health Survey? An Analysis of Three State Telephone Health Surveys 
Health Services Research  2010;45(5 Pt 1):1324-1344.
To examine the impact of response rate variation on survey estimates and costs in three health telephone surveys.
Data Source
Three telephone surveys of noninstitutionalized adults in Minnesota and Oklahoma conducted from 2003 to 2005.
Study Design
We examine differences in demographics and health measures by number of call attempts made before completion of the survey or whether the household initially refused to participate. We compare the point estimates we actually obtained with those we would have obtained with a less aggressive protocol and subsequent lower response rate. We also simulate what the effective sample sizes would have been if less aggressive protocols were followed.
Principal Findings
Unweighted bivariate analyses reveal many differences between early completers and those requiring more contacts and between those who initially refused to participate and those who did not. However, after making standard poststratification adjustments, no statistically significant differences were observed in the key health variables we examined between the early responders and the estimates derived from the full reporting sample.
Our findings demonstrate that for the surveys we examined, larger effective sample sizes (i.e., more statistical power) could have been achieved with the same amount of funding using less aggressive calling protocols. For some studies, money spent on aggressively pursuing high response rates could be better used to increase statistical power and/or to directly examine nonresponse bias.
PMCID: PMC2965507  PMID: 20579127
Health survey; response rates; health insurance; survey methods; drug use; health care access
4.  Feeling Good in Your Own Skin: The Influence of Complimentary Sexual Stereotypes on Risky Sexual Attitudes and Behaviors in a Community Sample of African American Women 
Women & health  2013;53(1):1-19.
Although negative racial stereotypes may affect the mental and physical health of African Americans, little research has examined the influence of positive or complimentary racial stereotypes on such outcomes. More specifically, this study explored the relationship between African American women’s endorsement of complimentary stereotypes about their sexuality (CSS) and attitudes/behaviors that have been associated with sexual risk. Data were gathered from 206 African American women as part of the Black Women in the Study of Epidemics project (B-WISE). Multivariate regression models were used to examine associations between women’s endorsement of CSS and selected sex-related attitudes and behaviors. Participants’ endorsement of CSS was significantly positively associated with beliefs that having sex without protection would strengthen their relationship (B = .28, SE = .10, p < .01) and that they could use drugs and always make healthy choices about using protection (B = .31, SE = .09, p < .01). Significant positive associations were also found between CSS and the number of casual sexual partners women reported in the past year (B = .29, SE = .15, p = .05) and their willingness to have sex in exchange for money or drugs during that time (B = .78, OR = 2.18, p < .05). These findings suggest that endorsement of CSS by African American women can lead to increased risk behavior, particularly relating to possible infection with HIV or other sexually transmitted infections (STI).
PMCID: PMC3579527  PMID: 23421336
5.  What Can Your Accountant Do For You? 
Canadian Family Physician  1977;23:39-40.
Physicians who complain about accountants' exhorbitant fees may not be getting their money's worth - because they aren't asking enough of their accountants. Besides preparing tax returns, accountants can set up bookkeeping procedures, advise on financial management and generally put the doctor more in control of his own income.
PMCID: PMC2378839
6.  A randomised, prospective study comparing trabeculectomy augmented with antimetabolites with a viscocanalostomy technique for the management of open angle glaucoma uncontrolled by medical therapy 
Aims: To compare trabeculectomy with viscocanalostomy for the control of intraocular pressure (IOP) in open angle glaucoma (OAG) uncontrolled by medical therapy.
Methods: 48 patients (50 eyes) with uncontrolled OAG were randomised to either trabeculectomy (25 eyes) or a viscocanalostomy technique (25 eyes). Preoperatively, eyes were graded in terms of risk factors for drainage failure. Those undergoing trabeculectomy were given intraoperative antimetabolites (5-fluorouracil 25 mg/ml (5-FU), mitomycin C (MMC) 0.2 mg/ml and 0.4 mg/ml) according to a standard protocol. Antimetabolites were not used intraoperatively in eyes undergoing viscocanalostomy, but they were randomised to the use of viscoelastic (Healonid GV) for intraoperative intracanalicular injection.
Results: There were no significant differences between the groups in age, sex, type of OAG, preoperative medications, risk factors for drainage failure, and preoperative IOP. Mean follow up was 19 months (range 6–24 months). It was 12 months or longer in all eyes, except one lost to follow up at 6 months. At 12 months, complete success (IOP <21 mm Hg without antiglaucoma medications) was seen in all eyes undergoing trabeculectomy (100%), but in only 64% of eyes undergoing viscocanalostomy (p<0.001). The mean IOP was lower at 12 months (p<0.001) with trabeculectomy and the number of eyes with IOPs of 15 mm Hg or less was greater (p<0.05). The mean IOP at 12 months was lower in eyes that had undergone viscocanalostomy using intraoperative intracanalicular Healonid GV injection compared to those where only balanced saline solution had been used (p<0.01). However, in terms of complete success there was no difference between the viscocanalostomy groups (p<0.1). With the exception of measurements at 1 week, visual recovery (logMAR acuity) was similar and laser flare and cell values showed little differences between the groups. Corneal topography and keratometry at 12 months were little different from preoperative values. Postoperative interventions (subconjunctival 5-FU and needling procedures) were similar between the groups. Transient complications such as early bleb leak and hyphaema were more common in the trabeculectomy group (p<0.05). Postoperative cataract formation was more common after trabeculectomy (p<0.05).
Conclusions: IOP control appears to be better with trabeculectomy. Viscocanalostomy is associated with fewer postoperative complications, although significant complications permanently impairing vision did not occur with either technique.
PMCID: PMC1771200  PMID: 12084743
trabeculectomy; viscocanalostomy
7.  Do You Use Your Head or Follow Your Heart? Self-Location Predicts Personality, Emotion, Decision Making, and Performance 
The head is thought to be rational and cold, whereas the heart is thought to be emotional and warm. Eight studies (total N = 725) pursued the idea that such body metaphors are widely consequential. Study 1 introduced a novel individual difference variable, one asking people to locate the self in the head or the heart. Irrespective of sex differences, head-locators characterized themselves as rational, logical, and interpersonally cold, whereas heart-locators characterized themselves as emotional, feminine, and interpersonally warm (Studies 1–3). Study 4 found that head-locators were more accurate in answering general knowledge questions and had higher GPAs and Study 5 found that heart-locators were more likely to favor emotional over rational considerations in moral decision-making. Study 6 linked self-locations to reactivity phenomena in daily life –e.g., heart-locators experienced greater negative emotion on high stressor days. Study 7 manipulated attention to the head versus the heart and found that head-pointing facilitated intellectual performance, whereas heart-pointing led to emotional decision-making. Study 8 replicated Study 3’s findings with a nearly year-long delay between the self-location and outcome measures. The findings converge on the importance of head-heart metaphors for understanding individual differences in cognition, emotion, and performance.
PMCID: PMC3722275  PMID: 23773045
Personality; Individual Differences; Metaphor; Cognition; Emotion; Performance
8.  Your client credibility: are your pharmacy practices helping or hindering? 
The Canadian Veterinary Journal  2004;45(8):695-699.
When recommending a specific pharmaceutical, more has to be taken into account than whether the API is indicated for the illness in question. Based on the preceding discussion, product source can have a tremendous impact on efficacy, on therapeutic success, and on practitioners' credibility in the eyes of their clients. However, product source goes beyond simple credibility, encompassing professional ethics and liability. In answering the Ethical question of the month--December 2001 "Should private veterinary practitioners be allowed to produce autogenous vaccines or compound antimicrobial products for use in food producing animals?" Rollin concluded, "one cannot envision a clearer case of unethical behavior." The reality is that quality assurance, efficacy, potency, and safety are not defined for compounded products, and should veterinarians choose to script or dispense one, the responsibility for its quality, efficacy, potency, and safety falls squarely on their shoulders. Ultimately, this also translates into 100% liability should an ADR, illness, or lack of effect, befall the patient. While having access to ELDU and compounded products is crucial in facilitating the treatment of the various diseases that veterinarians face, the regulatory freedom that gives them this choice carries heightened responsibilities when electing this option. In a nutshell, ethical and responsible principles of pharmacy dictate that a veterinarian's first choice should be a veterinary-licensed pharmaceutical for the indication in question. Should this not exist, ELDU of a licensed product with clinically derived therapeutic protocols should be the next choice. Compounded pharmaceuticals should only be used when no licensed (those sporting a DIN) product exists, and extreme cautions should be exercised when using transdermal formulations. Liability dictates that this decision be undertaken with informed consent of the owner and with appropriate due diligence when selecting a compounding service provider. Various articles have been written that provide the veterinarian with guidance when making this decision.
PMCID: PMC2751705  PMID: 15368747
9.  “You're just one of the group when you're embedded”: report from a mixed-method investigation of the research-embedded health librarian experience* 
Embedded librarianship has received much attention in recent years. A model of embeddedness rarely discussed to date is that of research-embedded health librarians (REHLs). This study explores the characteristics of Canadian REHLs and the situations in which they are employed.
The authors employed a sequential, mixed-method design. An online survey provided descriptive statistics about REHLs' positions and work experiences. This informed a series of focus group interviews that expanded upon the survey. Through constant comparison, we conducted qualitative descriptive analysis of the interviews.
Based on twenty-nine survey responses and four group interviews, we created a portrait of a “typical” REHL and discovered themes relevant to REHL work. REHLs may identify more strongly as researchers than as librarians, with corresponding professional needs and rewards. REHLs value “belonging” to the research team, involvement in full project lifecycles, and in-depth relationships with nonlibrarian colleagues. Despite widely expressed job satisfaction, many REHLs struggle with isolation from library and information science peers and relative lack of job security.
REHLs differ from non-embedded health librarians, as well as from other types of embedded librarians. REHLs' work also differs from just a decade or two ago, prior to widespread Internet access to digital resources.
Given that research-embedded librarianship appears to be a distinct and growing subset of health librarianship, libraries, master's of library and information science programs, and professional associations will need to respond to the support and education needs of REHLs or risk losing them to the health research field.
PMCID: PMC3794684  PMID: 24163600
10.  What is Your Understanding of Your Illness? A Communication Tool to Explore Patients’ Perspectives of Living with Advanced Illness 
Journal of General Internal Medicine  2012;27(11):1460-1466.
Provider communication courses and guidelines stress the use of open-ended questions, such as “what is your understanding of your illness?,” to explore patients’ perceptions of their illness severity, yet descriptions of patients’ responses are largely absent from the current literature. These questions are most often used by clinicians as they deliver bad news to cancer patients or address code status at the end of life, but have not been well studied in other diseases or earlier in the disease course.
To explore the responses of patients living with serious illness to the question “what is your understanding of your illness?” and to identify similarities and differences in themes and language used by cancer and non-cancer patients to discuss their illness.
We conducted a qualitative analysis of patients’ responses to “what is your understanding of your illness?”
Two hundred nine subjects, 69 with cancer, 70 CHF, and 70 COPD, who had an estimated 50 % 2-year survival. Mean age was 66 years.
Responses were recorded at the baseline interview of a larger, longitudinal study of patients with advanced life-limiting illness (cancer, CHF, or COPD). After thematic content analysis using open coding, investigators conducted pattern analysis to examine variation associated with diagnosis.
We identified five major themes: naming the diagnosis or describing the pathophysiology, illness history, prognosis, symptoms, and causality. Responses varied by diagnosis. Cancer patients’ responses more often included specific diagnostic details and prognosis, while non-cancer patients referenced symptoms and causality.
Patients’ responses to the open-ended question “what is your understanding of your illness?” can provide the clinician with important information and insight on how they view their illness in a non-acute setting. The identified themes can serve as a foundation for patient-centered communication strategies as we strive to build a mutual understanding of illness with patients.
PMCID: PMC3475827  PMID: 22638605
communication; qualitative research; advanced illness; patient-centered care; palliative care
11.  Preference-Based Serial Decision Dynamics: Your First Sushi Reveals Your Eating Order at the Sushi Table 
PLoS ONE  2014;9(5):e96653.
In everyday life, we regularly choose among multiple items serially such as playing music in a playlist or determining priorities in a to-do list. However, our behavioral strategy to determine the order of choice is poorly understood. Here we defined ‘the sushi problem’ as how we serially choose multiple items of different degrees of preference when multiple sequences are possible, and no particular order is necessarily better than another, given that all items will eventually be chosen. In the current study, participants selected seven sushi pieces sequentially at the lunch table, and we examined the relationship between eating order and preference. We found two dominant selection strategies, with one group selecting in order from most to least preferred, and the other doing the opposite, which were significantly different from patterns generated from a random strategy. Interestingly, we found that more females tended to employ the favorite-first rather than favorite-last strategy. These two choice sequences appear to reflect two opposing behavioral strategies that might provide selective advantages in their own right, while also helping to provide solutions to otherwise unconstrained problems.
PMCID: PMC4028175  PMID: 24846274
12.  “You’re losing your Ghanaianess”: understanding malaria decision-making among Africans visiting friends and relatives in the UK 
Malaria Journal  2014;13:287.
In the UK, the majority of imported malaria infections occur in the London area among UK residents of African origin who travel to Africa visiting friends and relatives (VFRs). Effective malaria prevention measures are available but there is little understanding of the factors that enhance and constrain their use among VFRs.
Semi-structured interviews were undertaken with Africans resident in London who visited friends and relatives in Nigeria and Ghana (n = 20) and with African VFRs recently treated for malaria (n = 6). Data collection took place between December 2007 and February 2011. Information on migration patterns and travel of respondents was collected and the data were analysed using a framework analysis approach.
Knowledge of the link between mosquitoes and malaria was high. Factors influencing the use of mosquito avoidance methods included knowledge about the local environment, perceptions of the inevitability of contracting malaria, and a desire to fit with the norms of host families. Previous experience of bed nets, and the belief that more modern ways of preventing mosquito bites were available deterred people from using them. Chemoprophylaxis use was varied and influenced by: perceptions about continuing immunity to malaria; previous experiences of malaria illness; the cost of chemoprophylaxis; beliefs about the likely severity of malaria infections; the influence of friends in the UK; and, the way malaria is perceived and managed in Nigeria and Ghana. Malaria treatment was considered by many to be superior in Nigeria and Ghana than in the UK. A conceptual framework was developed to illustrate the manner in which these factors interact to affect malaria decisions.
The use of malaria prevention among VFRs needs to be understood not only in terms of individual risk factors but also in relation to the context in which decisions are made. For VFRs, malaria decisions are undertaken across two distinct social and environmental contexts and within the structural constraints associated with each. Strategies for reducing the burden of malaria among VFRs that ignore this complexity are likely to face challenges. New approaches that take account of contextual as well as individual factors are required.
PMCID: PMC4118190  PMID: 25064713
Imported malaria; Africans visiting friends and relatives; Chemoprophylaxis; Malaria prevention; Malaria diagnosis; Malaria treatment; Migrant health
13.  A proposal for a primary screening tool: ‘Keep your waist circumference to less than half your height’ 
BMC Medicine  2014;12(1):207.
There is now overwhelming scientific evidence that central obesity, as opposed to total obesity assessed by body mass index (BMI), is associated with the most health risks and that the waist-to-height ratio (WHtR) is a simple proxy for this central fat distribution. This Opinion reviews the evidence for the use of WHtR to predict mortality and for its association with morbidity. A boundary value of WHtR of 0.5 has been proposed and become widely used. This translates into the simple screening message ‘Keep your waist to less than half your height’. Not only does this message appear to be suitable for all ethnic groups, it also works well with children.
Ignoring this simple message and continuing to use BMI as a sole indicator of risk would mean that 10% of the whole UK population, and more than 25% of the UK population who are judged to be normal weight using BMI, are misclassified and might not be alerted to the need to take care or to take action.
Accepting that a boundary value whereby WHtR should be less than 0.5 not only lends itself to the simple message ‘Keep your waist to less than half your height’ but it also provides a very cheap primary screening method for increased health risks: A piece of string, measuring exactly half a person’s height should fit around that person’s waist.
PMCID: PMC4223160  PMID: 25377944
Obesity; Waist-to-height ratio; Morbidity; Mortality
14.  The price of your soul: neural evidence for the non-utilitarian representation of sacred values 
Sacred values, such as those associated with religious or ethnic identity, underlie many important individual and group decisions in life, and individuals typically resist attempts to trade off their sacred values in exchange for material benefits. Deontological theory suggests that sacred values are processed based on rights and wrongs irrespective of outcomes, while utilitarian theory suggests that they are processed based on costs and benefits of potential outcomes, but which mode of processing an individual naturally uses is unknown. The study of decisions over sacred values is difficult because outcomes cannot typically be realized in a laboratory, and hence little is known about the neural representation and processing of sacred values. We used an experimental paradigm that used integrity as a proxy for sacredness and which paid real money to induce individuals to sell their personal values. Using functional magnetic resonance imaging (fMRI), we found that values that people refused to sell (sacred values) were associated with increased activity in the left temporoparietal junction and ventrolateral prefrontal cortex, regions previously associated with semantic rule retrieval. This suggests that sacred values affect behaviour through the retrieval and processing of deontic rules and not through a utilitarian evaluation of costs and benefits.
PMCID: PMC3260841  PMID: 22271790
functional magnetic resonance imaging; sacred values; utility; deontologic; rules
15.  Role of sodium hyaluronate (Healonid) in triangular flap trabeculectomy. 
The role of sodium hyaluronate (Healonid) in trabeculectomy to prevent a shallow or flat anterior chamber and hypotonia in the immediate postoperative period is reported. Twenty-nine eyes of 27 patients were included in a randomised controlled study. Thirteen eyes had trabeculectomy alone, and 16 eyes had trabeculectomy performed with Healonid injected into the anterior chamber. The results showed that shallowing of the anterior chamber and hypotonia occurred in both groups until day 21 postoperatively. There was no statistically significant difference between the two groups (p greater than 0.05). Healonid has no significant value in maintaining anterior chamber depth and preventing hypotonia in the early postoperative period following trabeculectomy.
PMCID: PMC1040521  PMID: 3880641
16.  Tears in your beer: Gender differences in coping drinking motives, depressive symptoms and drinking 
This study evaluates associations between coping drinking motives (CDM; drinking to regulate negative affect), depressive symptoms, and drinking behavior and extends the literature by also taking into account gender differences. Two hundred forty-three college students (Mean age = 22.93, SD = 6.29, 82% female) participated. Based on previous research, we expected that CDM would be positively associated with drinking and problems, particularly among those higher in depressive symptoms, as individuals experiencing higher levels of negative affect (i.e. depressive symptoms) and who drink to cope are likely to drink more and experience more alcohol-related problems. Lastly, based on established gender differences, we expected that CDM would be positively associated with drinking and problems, especially among females higher in depressive symptoms. Unexpectedly, findings suggested that CDMs were positively related to peak drinking, especially among those lower in depressive symptoms. Results further revealed a significant three-way interaction between CDM, depressive symptoms, and gender when predicting alcohol-related problems and drinking frequency. Specifically, we found that CDM were more strongly associated with problems among women who were lower in depressive symptoms; whereas CDM were more strongly associated with problems among men who were higher in depressive symptoms. These findings offer a more comprehensive depiction of the relationship between depressive symptoms, CDM, and drinking behavior by taking into account the importance of gender differences. These results provide additional support for considering gender when designing and implementing alcohol intervention strategies.
PMCID: PMC4267111  PMID: 25525419
alcohol; sex; motives; depressive symptoms
17.  “Getting sicker quicker”: Does living in a more deprived neighbourhood mean your health deteriorates faster? 
Health & Place  2012;18-20(2):132-137.
Data from the longitudinal West of Scotland Twenty-07 Study: Health in the Community was used to examine whether, over a 20 year period, the self-reported health of people living in deprived areas became poorer faster compared to those living in more affluent areas. Three cohorts (born in the early 1930s, 1950s and 1970s) are included, covering 60 years of the life span. Using multilevel growth curve models, a 40% probability of reporting poor health was predicted among residents of more deprived areas at an earlier age (66) compared to those living in more affluent areas (83). Wider area differences were seen for men than for women. Our findings indicate that attempts to reduce area differences in health should start young but also continue throughout the lifespan.
► Longitudinal data used to examine changes in self-reported health over a 20 year period. ► Health of people in poorer areas deteriorated faster than those in more affluent areas. ► 16 year gap between richer and poorer areas in odds of reporting poor health. ► Wider area differences were seen for men than for women.
PMCID: PMC3391685  PMID: 21873103
Area deprivation; Neighbourhood; Self-reported health; Longitudinal study; Health trajectories
18.  Current manufactured cigarette smoking and roll-your-own cigarette smoking in Thailand: findings from the 2009 Global Adult Tobacco Survey 
BMC Public Health  2013;13:277.
Current smoking prevalence in Thailand decreased from 1991 to 2004 and since that time the prevalence has remained flat. It has been suggested that one of the reasons that the prevalence of current smoking in Thailand has stopped decreasing is due to the use of RYO cigarettes. The aim of this study was to examine characteristics of users of manufactured and RYO cigarettes and dual users in Thailand, in order to determine whether there are differences in the characteristics of users of the different products.
The 2009 Global Adult Tobacco Survey (GATS Thailand) provides detailed information on current smoking patterns. GATS Thailand used a nationally and regionally representative probability sample of 20,566 adults (ages 15 years and above) who were chosen through stratified three-stage cluster sampling and then interviewed face-to-face.
The prevalence of current smoking among Thai adults was 45.6% for men and 3.1% for women. In all, 18.4% of men and 1.0% of women were current users of manufactured cigarettes only, while 15.8% of men and 1.7% of women were current users of RYO cigarettes only. 11.2% of men and 0.1% of women used both RYO and manufactured cigarettes. Users of manufactured cigarettes were younger and users of RYO were older. RYO smokers were more likely to live in rural areas. Smokers of manufactured cigarettes appeared to be more knowledgeable about the health risks of tobacco use. However, the difference was confounded with age and education; when demographic variables were controlled, the knowledge differences no longer remained. Smokers of manufactured cigarettes were more likely than dual users and those who used only RYO to report that they were planning on quitting in the next month. Users of RYO only appeared to be more addicted than the other two groups as measured by time to first cigarette.
There appears to be a need for product targeted cessation and prevention efforts that are directed toward specific population subgroups in Thailand and include information on manufactured and RYO cigarettes.
PMCID: PMC3621680  PMID: 23530750
Thailand; Manufactured cigarettes; Roll-your-own cigarettes (RYO); Prevalence of current smoking
19.  Make the most of your samples: Bayes factor estimators for high-dimensional models of sequence evolution 
BMC Bioinformatics  2013;14:85.
Accurate model comparison requires extensive computation times, especially for parameter-rich models of sequence evolution. In the Bayesian framework, model selection is typically performed through the evaluation of a Bayes factor, the ratio of two marginal likelihoods (one for each model). Recently introduced techniques to estimate (log) marginal likelihoods, such as path sampling and stepping-stone sampling, offer increased accuracy over the traditional harmonic mean estimator at an increased computational cost. Most often, each model’s marginal likelihood will be estimated individually, which leads the resulting Bayes factor to suffer from errors associated with each of these independent estimation processes.
We here assess the original ‘model-switch’ path sampling approach for direct Bayes factor estimation in phylogenetics, as well as an extension that uses more samples, to construct a direct path between two competing models, thereby eliminating the need to calculate each model’s marginal likelihood independently. Further, we provide a competing Bayes factor estimator using an adaptation of the recently introduced stepping-stone sampling algorithm and set out to determine appropriate settings for accurately calculating such Bayes factors, with context-dependent evolutionary models as an example. While we show that modest efforts are required to roughly identify the increase in model fit, only drastically increased computation times ensure the accuracy needed to detect more subtle details of the evolutionary process.
We show that our adaptation of stepping-stone sampling for direct Bayes factor calculation outperforms the original path sampling approach as well as an extension that exploits more samples. Our proposed approach for Bayes factor estimation also has preferable statistical properties over the use of individual marginal likelihood estimates for both models under comparison. Assuming a sigmoid function to determine the path between two competing models, we provide evidence that a single well-chosen sigmoid shape value requires less computational efforts in order to approximate the true value of the (log) Bayes factor compared to the original approach. We show that the (log) Bayes factors calculated using path sampling and stepping-stone sampling differ drastically from those estimated using either of the harmonic mean estimators, supporting earlier claims that the latter systematically overestimate the performance of high-dimensional models, which we show can lead to erroneous conclusions. Based on our results, we argue that highly accurate estimation of differences in model fit for high-dimensional models requires much more computational effort than suggested in recent studies on marginal likelihood estimation.
PMCID: PMC3651733  PMID: 23497171
20.  ‘Roll-your-own’ cigarette smoking in South Africa between 2007 and 2010 
BMC Public Health  2013;13:597.
The prevalence of smoking and consumption of cigarettes have decreased in South Africa over the last 20 years. This decrease is a result of comprehensive tobacco control legislation, particularly large cigarette tax increases. However, little attention has been given to the potential use of ‘roll-your-own’ cigarettes as cheaper alternatives, especially among the socio-economically disadvantaged population. This study therefore sought to determine socio-demographic correlates of ‘roll-your-own’ cigarette use among South African adults (2007–2010).
This secondary data analysis used a merged dataset from two nationally representative samples of 2 907 and 3 112 South African adults (aged ≥16 years) who participated in the 2007 and 2010 annual South African Social Attitude Surveys respectively. The surveys used a face-to-face interviewer-administered questionnaire. The overall response rates were 83.1% for 2007 and 88.9% for 2010. Data elicited included socio-demographic data, current smoking status, type of tobacco products used, past quit attempts and self-efficacy in quitting. Data analysis included chi-square statistics and multi-variable adjusted logistic regression analysis.
Of the 1 296 current smokers in this study, 24.1% (n = 306) reported using roll-your-own cigarettes. Some of whom also smoked factory-made cigarettes. Roll-your-own cigarette smoking was most common among black Africans and was more common among male smokers than among female smokers (27% vs 15.8%; p < 0.01). Compared to smokers who exclusively used factory-made cigarettes, roll-your-own cigarette smokers were less confident that they could quit, more likely to be less educated, and more likely to reside in rural areas. The odds of use of roll-your-own cigarette were significantly higher in 2010 than in 2007 (OR = 1.24; 95% CI: 1.07-1.44).
Despite an aggregate decline in smoking prevalence, roll-your-own cigarette smoking has increased and is particularly common among smokers in the lower socio-economic group. The findings also suggest the need for a more intensive treatment intervention to increase self-efficacy to quit among roll-your-own cigarette smokers.
PMCID: PMC3694453  PMID: 23800007
Smoking; Roll-your-own cigarettes; Factory-made cigarettes; South Africa; Self-efficacy; Quitting
21.  A penny for your thoughts: dimensions of self-generated thought content and relationships with individual differences in emotional wellbeing 
A core aspect of human cognition involves overcoming the constraints of the present environment by mentally simulating another time, place, or perspective. Although these self-generated processes confer many benefits, they can come at an important cost, and this cost is greater for some individuals than for others. Here we explore the possibility that the costs and benefits of self-generated thought depend, in part, upon its phenomenological content. To test these hypotheses, we first developed a novel thought sampling paradigm in which a large sample of young adults recalled several recurring thoughts and rated each thought on multiple content variables (i.e., valence, specificity, self-relevance, etc.). Next, we examined multi-level relationships among these content variables and used a hierarchical clustering approach to partition self-generated thought into distinct dimensions. Finally, we investigated whether these content dimensions predicted individual differences in the costs and benefits of the experience, assessed with questionnaires measuring emotional health and wellbeing. Individuals who characterized their thoughts as more negative and more personally significant scored higher on constructs associated with Depression and Trait Negative Affect, whereas those who characterized their thoughts as less specific scored higher on constructs linked to Rumination. In contrast, individuals who characterized their thoughts as more positive, less personally significant, and more specific scored higher on constructs linked to improved wellbeing (Mindfulness). Collectively, these findings suggest that the content of people’s inner thoughts can (1) be productively examined, (2) be distilled into several major dimensions, and (3) account for a large portion of variability in their functional outcomes.
PMCID: PMC3843223  PMID: 24376427
mind-wandering; autobiographical; rumination; depression; mindfulness
22.  Health benefits of 'grow your own' food in urban areas: implications for contaminated land risk assessment and risk management? 
Environmental Health  2009;8(Suppl 1):S6.
Compelling evidence of major health benefits of fruit and vegetable consumption, physical activity, and outdoor interaction with 'greenspace' have emerged in the past decade - all of which combine to give major potential health benefits from 'grow-your-own' (GYO) in urban areas. However, neither current risk assessment models nor risk management strategies for GYO in allotments and gardens give any consideration to these health benefits, despite their potential often to more than fully compensate the risks. Although urban environments are more contaminated by heavy metals, arsenic, polyaromatic hydrocarbons and dioxins than most rural agricultural areas, evidence is lacking for adverse health outcomes of GYO in UK urban areas. Rarely do pollutants in GYO food exceed statutory limits set for commercial food, and few people obtain the majority of their food from GYO. In the UK, soil contamination thresholds triggering closure or remediation of allotment and garden sites are based on precautionary principles, generating 'scares' that may negatively impact public health disproportionately to the actual health risks of exposure to toxins through own-grown food. By contrast, the health benefits of GYO are a direct counterpoint to the escalating public health crisis of 'obesity and sloth' caused by eating an excess of saturated fats, inadequate consumption of fresh fruit and vegetables combined with a lack of exercise. These are now amongst the most important preventable causes of illness and death. The health and wider societal benefits of 'grow-your-own' thus reveal a major limitation in current risk assessment methodologies which, in only considering risks, are unable to predict whether GYO on particular sites will, overall, have positive, negative, or no net effects on human health. This highlights a more general need for a new generation of risk assessment tools that also predict overall consequences for health to more effectively guide risk management in our increasingly risk-averse culture.
PMCID: PMC2796502  PMID: 20102591
23.  Your own actions influence how you perceive other people: A misattribution of action appraisals 
The attribution of personal traits to other persons depends on the actions the observer performs at the same time (Bach & Tipper, 2007). Here, we show that the effect reflects a misattribution of appraisals of the observers’ own actions to the actions of others. We exploited spatial compatibility effects to manipulate how fluently—how fast and how accurately—participants identified two individuals performing sporty or academic actions. The traits attributed to each person in a subsequent rating task depended on the fluency of participants’ responses in a specific manner. An individual more fluently identified while performing the academic action appeared more academic and less sporty. An individual more fluently identified while performing the sporty action appeared sportier. Thus, social perception is—at least partially—embodied. The ease of our own responses can be misattributed to the actions of others, affecting which personal traits are attributed to them.
PMCID: PMC2954360  PMID: 21633518
Social perception; Trait attribution; Fluency; Embodiment; Cingulate cortex; Action observation
24.  Moving Your Sons to Safety: Galls Containing Male Fig Wasps Expand into the Centre of Figs, Away From Enemies 
PLoS ONE  2012;7(1):e30833.
Figs are the inflorescences of fig trees (Ficus spp., Moraceae). They are shaped like a hollow ball, lined on their inner surface by numerous tiny female flowers. Pollination is carried out by host-specific fig wasps (Agaonidae). Female pollinators enter the figs through a narrow entrance gate and once inside can walk around on a platform generated by the stigmas of the flowers. They lay their eggs into the ovules, via the stigmas and styles, and also gall the flowers, causing the ovules to expand and their pedicels to elongate. A single pollinator larva develops in each galled ovule. Numerous species of non-pollinating fig wasps (NPFW, belonging to other families of Chalcidoidea) also make use of galled ovules in the figs. Some initiate galls, others make use of pollinator-generated galls, killing pollinator larvae. Most NPFW oviposit from the outside of figs, making peripherally-located pollinator larvae more prone to attack. Style length variation is high among monoecious Ficus spp. and pollinators mainly oviposit into more centrally-located ovules, with shorter styles. Style length variation is lower in male (wasp-producing) figs of dioecious Ficus spp., making ovules equally vulnerable to attack by NPFW at the time that pollinators oviposit.
We recorded the spatial distributions of galled ovules in mature male figs of the dioecious Ficus hirta in Southern China. The galls contained pollinators and three NPFW that kill them. Pollinators were concentrated in galls located towards the centre of the figs, NPFW towards the periphery. Due to greater pedicel elongation by male galls, male pollinators became located in more central galls than their females, and so were less likely to be attacked. This helps ensure that sufficient males survive, despite strongly female-biased sex ratios, and may be a consequence of the pollinator females laying mostly male eggs at the start of oviposition sequences.
PMCID: PMC3266273  PMID: 22295113
25.  Fight for your breeding right: hierarchy re-establishment predicts aggression in a social queue 
Biology Letters  2010;7(2):190-193.
Social aggression is one of the most conspicuous features of animal societies, yet little is known about the causes of individual variation in aggression within social hierarchies. Recent theory suggests that when individuals form queues for breeding, variation in social aggression by non-breeding group members is related to their probability of inheriting breeding status. However, levels of aggression could also vary as a temporary response to changes in the hierarchy, with individuals becoming more aggressive as they ascend in rank, in order to re-establish dominance relationships. Using the group-living fish, Neolamprologus pulcher, we show that subordinates became more aggressive after they ascended in rank. Female ascenders exhibited more rapid increases in aggression than males, and the increased aggression was primarily directed towards group members of adjacent rather than non-adjacent rank, suggesting that social aggression was related to conflict over rank. Elevated aggression by ascenders was not sustained over time, there was no relationship between rank and aggression in stable groups, and aggression given by ascenders was not sex-biased. Together, these results suggest that the need to re-establish dominance relationships following rank ascension is an important determinant of variation in aggression in animal societies.
PMCID: PMC3061154  PMID: 20880857
aggression; dominance hierarchy; conflict over rank; Neolamprologus pulcher

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