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Secondhand smoke (SHS) exposure causes cardiovascular disease, lung cancer and pulmonary disorders. Smoke-free policies are the most effective way to prevent exposure to SHS. A 5-year community-based randomized control trial (RCT) is in progress to assess factors associated with smoke-free policy development in rural communities. Considering secular trends is critical when conducting community-based RCTs as they may threaten the internal validity of the study. For the purposes of this paper, secular trends are defined as patterns or recurring events that are not directly related to smoke-free policy but have the potential to influence policy development. There are no established protocols to monitor secular trends in the study of smoke-free policy in rural communities. The purpose of this paper is to (i) describe the development of a protocol to identify and monitor secular trends that may threaten the internal validity of a community-based RCT to promote smoke-free policy development and (ii) describe secular trends identified in the first 2 years of the RCT. The sample includes 854 secular events captured from media outlets covering the 40 study counties over the first 2 years of the RCT. Of these 854 events, there were 281 secular events in Year 1 and 573 in Year 2. This paper focuses on five specific categories: ‘tobacco use and cessation activities’, ‘farming’, ‘economics’, ‘city/county infrastructure’ and ‘wellness’. This protocol is a feasible yet time-intensive method of identifying events that may threaten the internal validity of a community-based RCT.
Serious short- and long-term adverse health outcomes are associated with exposure to secondhand smoke (SHS), including cardiovascular disease, lung cancer, sudden infant death syndrome, other alterations in respiratory function and many other health conditions . Even brief exposure to SHS can lead to heart attacks .
Smoke-free policies are the most effective way to shield the public from SHS exposure and the associated health risks. The Task Force on Community Preventive Services strongly recommended smoke-free policies on the basis of scientific evidence that they protect people from SHS exposure. The Task Force also noted that such policies are associated with increased use of tobacco use cessation resources and reduced smoking prevalence . Policies that prohibit smoking entirely decrease SHS exposure more than policies that simply limit smoking to specific areas . The elimination of tobacco smoking in workplaces through comprehensive smoke-free policy has significantly improved indoor air quality [5, 6, 7] and the adverse health effects associated with SHS exposure . After strong smoke-free laws go into effect, communities experience a 15% drop in heart attacks during the first year, with continued declines of 36% in 3 years . The ultimate goals of smoke-free policies as noted in the Fundamentals of Smoke-free Workplace Laws are to protect citizens from SHS exposure, promote healthier communities and establish smoke-free environments as the norm .
A 5-year community-based randomized control trial (RCT) to test the effects of a stage-based, tailored intervention on policy outcomes is currently in progress in rural Kentucky. While building capacity, resources and tobacco control efforts at the community level can help advocates advance tobacco-free policy , policy outcomes may not be solely attributed to tobacco control interventions. Community events unrelated to smoke-free policy may impact the outcomes of community-based interventions and threaten internal validity of RCTs. For example, a rural community may receive a large grant to bolster the tobacco farming infrastructure.
It is necessary to measure secular trends when conducting RCTs because community events may exert such a profound force that program interventions see few or no effects . On the other hand, certain events may steer the results in a positive direction, such that the interventions alone are not fully responsible for the favorable outcomes observed . To fully account for these potentially confounding external occurrences during RCTs and reduce the threats to internal validity, it is essential to pay careful attention to the contribution of secular trends, which can dilute or strengthen community outcomes. Although the importance of monitoring secular trends in intervention studies is well documented [12, 13], the process for monitoring them is not well understood.
The primary purpose of the paper is to describe the development of a protocol to identify and monitor secular trends that may threaten the internal validity of a community-based RCT to promote smoke-free policy development in rural Kentucky. A secondary purpose of this paper is to describe secular trends identified in the first 2 years of the RCT. For the purposes of this study, secular trends are patterns of events unrelated to smoke-free policy that may indirectly influence the results of the community RCT.
The larger study is a community-based RCT, in which 40 rural Kentucky counties were randomized into Treatment (n = 22), Control I (n = 8) and Control II (n = 10). Counties were eligible to be selected if they were rural, defined as outside the metropolitan statistical areas . For multi-county health department districts, one county was randomly chosen; this omitted 27 of the 99 rural Kentucky counties from further consideration. From the remaining pool of 72 rural counties, 40 were randomly selected with the additional criterion that none were geographically contiguous. By not choosing counties within the same health department district, or neighboring counties, the potential for contamination was minimized.
The treatment counties receive annual readiness assessments and stage-based, tailored technical assistance to move toward smoke-free policy. Control I counties receive annual community readiness assessments with key informants and elected officials but no tailored technical assistance. Control II counties receive only a readiness assessment at the end of the Year 5. The Control II condition was seen as necessary because preliminary work with the readiness tool indicated it may act as an intervention. A protocol to identify and monitor secular trends in all 40 study counties was developed at the beginning of the project.
Over the first 2 years of the RCT, 854 secular events were identified from media outlets covering the 40 study counties. For the purpose of this paper, a secular event is defined as an occurrence that falls into one of the predetermined categories (see Table I). A secular trend is defined as a reoccurrence or pattern in secular events. For example, a business closing would be a secular event. A downturn in the economy, leading to multiple business closings and a rise in the unemployment rate, would likely be the focus of multiple events across several counties and would become a secular trend. A category refers to specific types of secular trends, such as ‘tobacco use and cessation activities’ or ‘farming’ (see Table I for full list).
The development of the secular trend monitoring protocol began with the selection of relevant categories. Few research articles describe the procedures for tracking secular trends. Fewer published papers detail the secular events or trends most likely to impact the development of a smoke-free policy. No articles were identified that included a procedure for monitoring secular trends related to the development of smoke-free policy.
Potentially relevant categories were identified a priori from the literature review and the team's smoke-free policy and community experience. The team consists of subject area experts, as well as project staff with tobacco control field experience. The research team initially identified 12 categories and developed detailed definitions of each that were used loosely as broad inclusion criteria (see Table I).
An iterative process was used to develop and refine the categories and definitions based on data collected during the first year. The person who monitored secular events was a student or staff member, and they were trained by the investigative team in the protocol as it developed. Although one monitor selected and coded the articles, they were closely supervised by members of the research team.
As the monitor reviewed the relevant data, they discovered new categories with potential to threaten internal validity. For example, the ‘politics’ category was added in Year 2 because many local media sources covered the presidential campaign and the national election. Subsequent political movements advocating for limited government (i.e. tea party movement) might also affect smoke-free policy development and threaten internal validity.
Internet-based surveillance was the foundation for gathering information on secular events. Weekly to bimonthly (twice per month), the monitor reads the Commonwealth Newsflash, an online newsletter on statewide news highlights. The monitor accesses and searches all electronically available newspapers bimonthly plus radio and television station websites from each of the 40 study counties. All new information that is readily available on the website (i.e. not in the archives) from the 2-week period is reviewed. The monitor uses the definitions of the categories outlined in Table I to decide what events are relevant for inclusion in the database.
The majority of secular trends are identified through the newspaper, radio or television station websites; however, other methods are also used. Monthly, the monitor reviews the city/county, health department, school system and Chamber of Commerce web pages from each county. While the majority of the web-based secular trend queries is conducted by the monitor, the entire research team scans and forwards any applicable articles. Additionally, community advisors who provide the tailored technical assistance to treatment communities notify the monitor of important secular issues that arise. Table II summarizes the timeline for Internet-based searching by media outlet.
Some smaller counties lack electronic media outlets, complicating the collection of secular trend information for all communities. In this case, the monitor completes an Internet search by means of a general search engine (Google) to acquire information about the county or a nearby community. News sources are the most effective medium for secular event surveillance due to their ability to capture stories of interest to the public, illuminate current public problems and triumphs and influence a broad, impressionable audience .
Although the focus of the secular trend analysis is at the local community level, relevant state and national articles are also collected and analyzed. Articles from professional journals, listserv communication and televised media reports of all state and national events that may influence local level smoke-free policy development are considered.
Bimonthly, the monitor saves all articles that cover one or more secular events in a password protected file (see Table I). Each month, the monitor codes and files the articles. Quarterly, summaries are prepared on a report sheet, which includes the number of events per county and study group (Treatment, Control I and Control II). Recurring events over time are defined as secular trends. A more detailed discussion of the literature basis of selected categories of secular events follows. For the purpose of this paper, the five categories that were either the most prevalent during the first 2 years of the study or supported by the literature will be highlighted: ‘tobacco use and cessation activities’, ‘farming’, ‘economics’, ‘city/county infrastructure’ and ‘wellness’.
Articles describing community events concerning tobacco use and tobacco control are integral to the surveillance of secular trends that might influence smoke-free policy development. Smoking cessation programs, testimonies by former smokers and other smoking-related events can threaten the internal validity of a study on smoke-free policy development. According to the experience of the research team, opinion pieces, editorials and personal stories influence the community's readiness for smoke-free policy. For example, a story about a school youth group starting a smoking cessation campaign may influence the community climate to positively support smoke-free policy. Conversely, an editorial on the individual right to smoke may negatively influence community climate toward government regulation of smoking.
Smoking cessation and rates of smoking in a community are particularly important because smoking status may be linked to support of or opposition to smoke-free policy. In a survey of multiple states, non-smokers were more likely to favor a mandate prohibiting smoking in restaurants than smokers . Communities with resources to provide and market programs that mobilize citizens to quit smoking may influence community support for smoke-free policy. Likewise, high smoking rates and few tobacco treatment resources may potentially foster a climate that might discourage support for a smoke-free law.
County economic conditions must be monitored closely to track situations that may jeopardize or bolster readiness for smoke-free policy and policy outcomes. According to a study of Wisconsin cities, a community's wealth can influence the passage of an ordinance, with adjusted gross income being greater in cities that adopted restaurant smoke-free policies . If events positively impact a county's economy, such as new employment opportunities or business openings, the citizens and policymakers may be more likely to embrace government regulation. On the other hand, business closings or revenue loss may indicate that a community is experiencing an economic downturn. The economic climate may threaten the internal validity of any study designed to test the effects of a community-based intervention on community outcomes.
Farming is another topic that might influence smoke-free policy development and/or implementation, especially in tobacco-growing regions. The monitor searches for secular events related to the development of a new crop, the loss of farmland or weather affecting crops. Kentucky traditionally is home to many small family farms that grow tobacco as a major cash crop . Since the federal tobacco buyout in 2004, more farmers contract directly with the tobacco industry to sell their tobacco . Since the industry sells to a global market, local smoke-free policies may not impact the farmer's bottom line . Nonetheless, raising tobacco is an historical and cultural icon in Kentucky and remains an emotional issue in communities with a heritage of cultivating the crop . Tobacco companies capitalize on this cultural and nostalgic value and promote their goods by distributing videos with cheerful clips of farming and personal testimonies by farmers, associating tobacco growing with love for country and national pride .
For farmers and people living in tobacco-producing communities, smoke-free policy may be unwelcome and interpreted as compromising the economic and cultural fabric of their communities. Although most state legislators strongly favored agricultural overhauls in the mid-1990s to curb Kentucky's overwhelming reliance on tobacco, officials who owned tobacco land were more reluctant to endorse alternative farming modalities, smoke-free policies and advertising limitations . Such resistance by individuals with investment in tobacco farming may impact the development of smoke-free policy in rural communities and may threaten internal validity.
When tracking secular events, it is essential for the monitor to document articles involving systems associated with city and/or county government. Examples include emergency medical services, health departments and fire departments. In Massachusetts, researchers discovered that financial support by the local board of health corresponded with stronger smoke-free restaurant policies . Events which increase or decrease board of health support or shift the board of health's focus may influence the adoption of smoke-free policies.
Based on the research team's experience, if a city or county's infrastructure is enhanced in such a way that new resources become available, the capacity to enact smoke-free laws may be enhanced. Conversely, some events may affect the infrastructure in a deleterious fashion, such that the public and elected officials focus their efforts on restoring the city or county's condition. A natural disaster is an example of such a situation. In this case, concerns for passing smoke-free policy might be replaced by a higher priority agenda (such as rebuilding damaged businesses and homes).
This category encompasses events pertaining to obesity, cancer, diabetes, cardiovascular disease and other significant health problems, in addition to discussions of primary prevention in public health. Local health departments frequently tackle wellness issues and promote positive lifestyle changes to community residents, and most adopt a multifaceted approach by simultaneously targeting several health-related issues. In New York City, for example, public health programs and projects have addressed posting fat and calorie information at restaurants, immunizations, diabetes control and safe sexual activity, in addition to smoke-free policy . Rural areas also maintain a holistic emphasis by focusing on many aspects of health and wellness. Consequently, measures aimed at reducing the prevalence of a particular disease or problem may simultaneously heighten awareness of other conditions. For example, a program emphasizing weight loss and exercise may cause community residents to desire, achieve and maintain a healthy lifestyle. Also, events such as Relay for Life and Race for the Cure illuminate cancer and can potentially mobilize citizens to be vigilant in preventing cancer development in the community. Smoke-free policy may be indirectly advanced due to these secular events, as the county's population becomes interested in overall wellness and prevention of disease. Alternately, secular events may divert attention away from smoke-free regulations. If a particular community struggles with very high rates of teen pregnancy, for example, residents and health professionals may focus the majority of their efforts and resources on addressing that particular issue, reducing the effects of study interventions and compromising internal validity.
While the full analysis of secular trend data will not occur until the end of the RCT, we describe secular events from the first 2 years of monitoring to demonstrate the usability of the protocol. Results presented here include descriptive statistics, as well as an in-depth look at five secular event categories: tobacco use and cessation activities, farming, economics, city/county infrastructure and wellness.
The sample was the 854 secular events captured from media outlets covering 40 counties during the first 2 years of the study. In Year 1, there were 281 secular events, with 171 in Treatment, 49 in Control I and 61 in Control II communities. In Year 2, there were 573 secular events, with 428 in Treatment, 45 in Control I and 100 in Control II.
Table III provides data on the number and percentage of secular events per study year (Year 1 or Year 2) and community type (Treatment, Control I and Control II). The category of wellness was most prevalent across all three study groups, except in Control I counties in Year 1. Throughout the entire period of data collection, there have been no ‘influential citizen’ articles in any study group. Following the most prevalent secular event of wellness, Treatment counties have primarily experienced events related to economics and city/county infrastructure over the 2-year period. Control I counties have been affected primarily by city/county infrastructure and education/school system issues. Similarly, secular events in Control II counties have been primarily related to city/county infrastructure, following wellness.
Table IV summarizes the percent change in secular events by category from Year 1 to Year 2. In Treatment communities, secular events related to farming, economics and wellness declined; whereas events related to tobacco use and cessation activities and city/county infrastructure increased from Year 1 to Year 2. In Control I communities, secular events related to tobacco use and cessation activities, economics and city/county infrastructure declined and those related to farming and wellness increased over time. For Control II communities, secular events decreased related to tobacco use and cessation activities and wellness but increased for farming, city/county infrastructure and economics.
Among Treatment communities, the percentage of articles coded as tobacco use and cessation increased 16.7% from Year 1 to Year 2, whereas the percentage decreased by 100% in both Control I and Control II communities. One example of an event coded as tobacco use and cessation activities from one Treatment community in Year 2 was that the school board was considering purchasing a device to reduce student smoking in the restrooms. Upon detecting smoke, the device would not only notify school officials but also instruct the student to leave the bathroom . Other examples of the tobacco use and cessation activities category include advertisements for health department smoking cessation classes.
Across Treatment communities, there was a 70.3% decrease in farming-related articles from Year 1 to Year 2 compared with a 10% increase in Control I communities and a 25% increase in Control II communities. In Year 1, there was a severe drought that affected farmers across Kentucky. The entire state of Kentucky was designated a natural disaster area by the US Department of Agriculture. In one of the treatment communities, an associated press article informed farmers about applying for emergency, low interest loans. The discussion of loss of tobacco crops spanned six paragraphs . Other examples of topics discussed in the farming category included local farmers’ markets and special interest stories featuring local farmers.
From Year 1 to Year 2, in Treatment communities, there was an 11.6% decrease in secular events related to economics. In Control I communities, there was a 9% decrease, and in Control II, there was a 104.1% increase. In Year 2, the unemployment rate in one of the Control II counties rose to a level higher than both the state and national average and there were reports of layoffs at two local businesses and a downturn in the housing market . Another example of an economics-related event was related to a clean coal bill reported in one of the Control II counties. According to the article, ‘Political leaders in Kentucky, worried about the future of coal amid ever-increasing environmental demands, have taken action that they say is critical to protecting a mainstay of the state's economy’ . Reports of business openings and closings were other examples of the economics category of secular events.
Among Treatment communities, there was a 47.9% increase in events related to city/county infrastructure compared with a 25.2% decrease in Control I communities and a 55.4% increase in Control II communities. As an example, in Year 2, many study communities’ city or county governments were affected by the rising cost of fuel. Another example of a city/county infrastructure event occurred when a county Health Department in one Treatment county received a grant to fund services as well as construction. Among other services, the grant would provide money for nurses in the school system . Other examples include increases in tax rates, infrastructure improvements and grants applied for or received by the city or county government.
Although there was a decrease in wellness articles in Treatment (24.3%) and Control II (0.8%) communities, there was a large increase among Control I communities (225.6%). An example of an event that occurs annually across many of the study communities is Relay for Life, a large-scale event designed to raise awareness and funds for cancer research. In several of the rural communities included in this study, Relay for Life generated multiple news articles each year. Examples of topics included stories advertising the event or reporting the estimated turnout or amount of money raised. Other examples of secular events that were captured included the opening of parks or wellness centers.
The first purpose of this paper was to describe a protocol for monitoring secular trends as part of a 5-year, community-based RCT on smoke-free policies in a rural, tobacco-producing state. This paper presents a systematic, feasible protocol for identifying, operationalizing and monitoring secular events that might impact the outcomes of community-based RCTs. It is important to monitor secular trends because they may mask the effects of interventions tested by RCTs and threaten internal validity. The method for monitoring secular trend analysis is not well defined in the literature. The protocol presented in this paper may be helpful to researchers conducting community-based RCTs on a variety of health topics.
Secular trend monitoring begins with identification and selection of relevant categories. These categories should be selected based on literature review and community experience. Although there may be some overlap to those selected for this protocol, the categories selected must be individualized to the topic area. For example, investigators conducting a community-based RCT to test an intervention designed to reduce human immunodeficiency virus transmission will likely also be interested in monitoring community-wide wellness campaigns. However, instead of capturing articles on tobacco cessation or smoking prevalence rates, secular events related to safe sex seminars or sexually transmitted disease prevalence rates may be more appropriate.
The next step to monitoring secular trends is deciding on the frequency of monitoring. This decision should be made based on the types of media available in the area. For this project, a statewide newsletter is reviewed weekly; newspaper articles are monitored biweekly and other websites (i.e. health departments and schools), as well as Google searches, are conducted monthly.
The second purpose of this paper was to provide preliminary results of the first 2 years of secular trend monitoring. The research team counts the number of secular events per category, as well as compares percent change over time by study group (Treatment, Control I and Control II). Secular trends, or patterns of secular events, may be considered possible threats to internal validity. For example, among Treatment communities, there was an increase in tobacco use and cessation activities.
In the case of the smoke detector devices installed in school restrooms to address student smoking, the impact of this one event on community outcomes is unknown, but when considered together with other similar secular events of this category, this may curb youth tobacco use and focus the community's attention on other ways of addressing the tobacco problem. A reduction in the smoking rate may motivate the community to embrace policy development, as a greater percentage of non-smokers, compared with smokers, support smoke-free policies . This example illustrates that it will be important to analyze both individual secular events and secular trends at the close of the RCT to determine unique influences within and across communities. If Treatment communities are more successful than Controls at enacting and implementing smoke-free laws at the end of the 5-year study, it will be important to consider whether these secular trends played a role in the outcomes or if they were due primarily to the intervention.
At this time, the data have been largely analyzed at the level of study group (Treatment, Control I and Control II). However, at the completion of the study, secular events and trends will also be examined at the individual county level. Quantitative, descriptive data are valuable in assessing which events may be recurring secular trends. These data may also be used as control variables in future analyses.
Although these data are valuable in assessing secular trends, the overall analysis of the impact of secular trends as a potential threat to internal validity will be conducted qualitatively. Qualitative data may be more useful in describing the magnitude of possible effects on smoke-free policy. For example, a series of articles on smoking cessation classes and an article on an increase in the prevalence of adult smoking would both be coded as tobacco use and cessation activities. The qualitative analysis of these articles would be important to consider in differentiating whether the secular events would likely have a positive or negative effect on policy outcomes. Similarly, in the case of the health department that received a grant supporting school nurses, qualitative data are needed to determine the magnitude of impact that this might have on smoke-free law development. A $100000 grant would not have nearly the same impact as one for $1000000.
There are limitations to secular trend analysis. First, the monitor must use his or her judgment using a broad list of inclusion criteria to determine if a particular article might be relevant to the outcome of interest (i.e. smoke-free policy development in rural communities). With only a single monitor, there is potential for error. In future studies that monitor secular trends, it is recommended that two people independently code a sample of the articles to determine inter-rater reliability.
Second, due to the timing of the media searches, it is possible that certain relevant events will be missed. This is particularly possible for communities that do not have online newspapers. In addition, every 2 weeks, all stories available on the newspaper's main page are searched, but some relevant secular events may be missed. In future studies, it may be beneficial to search more frequently. In addition, other methods of identifying secular events may be considered. One possibility could be quarterly surveys of leaders in each study community.
Third, community events may fit into more than one category. Consider the previous example of the health department receiving a grant to fund school nurses. While this article was coded city/county infrastructure, it is also a wellness and an ‘education/school system’ article.
Another limitation to this data analysis is the sample size of secular events. Although there were 854 events captured overall, these events were divided by county type (Treatment, Control I or Control II) and category. The sample size must be taken into consideration when evaluating the percent change. For example, there was a 225.6% increase in wellness from Year 1 to Year 2 in Control I communities, but the actual number of events increased from 4 to 12.
This paper described a protocol for identifying and monitoring secular events in 40 study counties in rural Kentucky that are part of a larger 5-year RCT to test the effects of a stage-based, tailored community-based intervention on smoke-free policy outcomes. Secular trend monitoring is a feasible yet time-intensive method of collecting data on events that might confound the results of a community-based RCT and threaten internal validity. This paper described data from Years 1 and 2 in Treatment and Control groups and considered how these data may be used to interpret the effects of the intervention.
National Heart, Lung and Blood Institute (Award Number R01HL086450) to E.J.H., Principal Investigator
The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Heart, Lung and Blood Institute or the National Institutes of Health.