Search tips
Search criteria

Results 1-7 (7)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Association between psychological symptoms in adults and growth in early life: longitudinal follow up study 
BMJ : British Medical Journal  2002;325(7367):749.
To test the hypothesis that birth weight for gestational age and weight gain in early childhood have a long term association with psychological distress in adults.
Longitudinal study of 1958 birth cohort followed to age 42 years.
Population based birth cohort study.
9731 cohort members with valid perinatal, postnatal, and adult data.
Main outcome measures
Malaise inventory scores measured at ages 23, 33, and 42 years. Generalised estimating equations approach used to analyse repeated measures.
Psychological distress score was inversely related to birthweight z score and weight gain from birth to the age of 7 years. A unit increase in birthweight z score or childhood weight gain was associated with a mean reduction in psychological distress score of 0.10 (95% confidence interval 0.05 to 0.15) and 0.06 (0.02 to 0.10), respectively. Birth weight and weight gain were also inversely related to the odds of having a high level of psychological distress, with odds ratios being 0.90 (0.85 to 0.95) and 0.93 (0.89 to 0.98), respectively.
Psychological health in adults is related to fetal growth and growth in early childhood.
What is already known on this topicPsychological outcomes in children are related to fetal growth and postnatal growthSize at birth is also associated with psychological outcomes in adolescents and young adultsWhat this study addsBoth birthweight z score and weight gain in early childhood are associated with psychological distress at ages 23 to 42The impact of a smaller size at birth may be compensated for by a higher postnatal weight gain
PMCID: PMC128376  PMID: 12364303
2.  A Simple Approach to the Estimation of Incidence Rate Difference 
American Journal of Epidemiology  2010;172(3):334-343.
The incidence rate difference (IRD) is a parameter of interest in many medical studies. For example, in vaccine studies, it is interpreted as the vaccine-attributable reduction in disease incidence. This is an important parameter, because it shows the public health impact of an intervention. The IRD is difficult to estimate for various reasons, especially when there are quantitative covariates or the duration of follow-up is variable. In this paper, the authors propose an approach based on weighted least-squares regression for estimating the IRD. It is very easy to implement because it boils down to performing ordinary least-squares regression analysis of transformed variables. Furthermore, if the outcome events are repeatable, the authors propose that data on all events be analyzed instead of first events only. Four versions of the Huber-White robust standard error are considered for statistical inference. Simulation studies are used to examine the performance of the proposed method. In a variety of scenarios simulated, the method provides an unbiased estimate for the IRD, and the empirical coverage proportion of the 95% confidence interval is very close to the nominal level. The method is illustrated with data from a vaccine trial carried out in the Gambia in 2001–2004.
PMCID: PMC2917058  PMID: 20606039
incidence rate; least-squares analysis; recurrent events; standard error
3.  Pneumococcal Nasopharyngeal Carriage following Reduced Doses of a 7-Valent Pneumococcal Conjugate Vaccine and a 23-Valent Pneumococcal Polysaccharide Vaccine Booster▿ †  
Clinical and Vaccine Immunology : CVI  2010;17(12):1970-1976.
This study was conducted to evaluate the effect of a reduced-dose 7-valent pneumococcal conjugate vaccine (PCV) primary series followed by a 23-valent pneumococcal polysaccharide vaccine (23vPPS) booster on nasopharyngeal (NP) pneumococcal carriage. For this purpose, Fijian infants aged 6 weeks were randomized to receive 0, 1, 2, or 3 PCV doses. Within each group, half received 23vPPS at 12 months. NP swabs were taken at 6, 9, 12, and 17 months and were cultured for Streptococcus pneumoniae. Isolates were serotyped by multiplex PCR and a reverse line blot assay. There were no significant differences in PCV vaccine type (VT) carriage between the 3- and 2-dose groups at 12 months. NP VT carriage was significantly higher (P, <0.01) in the unvaccinated group than in the 3-dose group at the age of 9 months. There appeared to be a PCV dose effect in the cumulative proportion of infants carrying the VT, with less VT carriage occurring with more doses of PCV. Non-PCV serotype (NVT) carriage rates were similar for all PCV groups. When groups were pooled by receipt or nonreceipt of 23vPPS at 12 months, there were no differences in pneumococcal, VT, or NVT carriage rates between the 2 groups at the age of 17 months. In conclusion, there appeared to be a PCV dose effect on VT carriage, with less VT carriage occurring with more doses of PCV. By the age of 17 months, NVT carriage rates were similar for all groups. 23vPPS had no impact on carriage, despite the substantial boosts in antibody levels.
PMCID: PMC3008188  PMID: 20943882
4.  Safety and Immunogenicity of the 23-Valent Pneumococcal Polysaccharide Vaccine at 12 months of age, following One, Two, or Threes Doses of the 7-valent Pneumococcal Conjugate Vaccine in Infancy 
Vaccine  2010;28(18):3086-3094.
Fijian infants aged 6 weeks were stratified by ethnicity and randomized to receive 0, 1, 2, or 3 PCV-7 doses with or without the 23-valent pneumococcal polysaccharide vaccine (PPV-23) at 12 months. Strong booster effects for all 7 PCV-7 serotypes were elicited, and for 4/7 serotypes these responses were highest in the single PCV-7 group. There were fourfold rises in GMC for all non-PCV-7 serotypes. By 17 months the PPV-23 group still had significantly higher GMC (each p<0.001) for all serotypes. The PPV-23 was well tolerated and induced excellent responses for all serotypes which were greatest in the single PCV-7 group.
PMCID: PMC2857918  PMID: 20199764
Pneumococcal; polysaccharide; booster
5.  Validation of the English and Chinese versions of the Quick-FLIC quality of life questionnaire 
British Journal of Cancer  2005;92(4):668-672.
A useful measure of quality of life should be easy and quick to complete. Recently, we reported the development and validation of a shortened Chinese version of the Functional Living Index – Cancer (FLIC), which we called the Quick-FLIC. In the present study of 327 English-speaking and 221 Chinese-speaking cancer patients, we validated the English version of the Quick-FLIC and further assessed the Chinese version. The 11 Quick-FLIC items were administered alongside the 11 remaining items of the full FLIC, but there appeared to be little context effect. Validity of the English version of the Quick-FLIC was attested by its strong correlation with two other measures of quality of life, and its ability to detect differences between patients with different performance status and treatment status (each P<0.001). Its internal consistency (alpha=0.86) and test–retest reliability (intraclass correlation=0.76) were also satisfactory. The measure was responsive to changes in performance status (P<0.001). The Chinese version showed similar characteristics. The Quick-FLIC behaved in ways that are highly comparable with the FLIC, even though the Quick-FLIC comprised only 11 items whereas the FLIC comprised 22. Further research is required to see whether the use of shorter instruments can improve data quality and response rates, but the fact that shorter instruments place less burden on the patients is itself inherently important.
PMCID: PMC2361884  PMID: 15700037
quality of life; shortening; validation
6.  Quick-FLIC: validation of a short questionnaire for assessing quality of life of cancer patients 
British Journal of Cancer  2004;90(9):1747-1752.
PMCID: PMC2409739  PMID: 15150626
quality of life; shortening

Results 1-7 (7)