BACKGROUND Fewer than 5 % of cancer patients participate in clinical research. Although this paltry rate has led to extensive research on this topic, previous studies have not sought verbatim comments in a real-time, comprehensive manner to understand why patients decline. METHODS This study used a low-risk, non-interventional parent study that focused on cancer-associated weight loss to unde...

OBJECTIVES To evaluate the reliability, magnitude and direction of the resulting bias in the application of a screening instrument for mental disorders by considering proxy informants in comparison to primary informants. METHODS Data are taken from a general morbidity community-based survey carried out in 520 randomly selected households of an industrial area of the Metropolitan Region of Sal...

BACKGROUND To test seven different strategies for recruitment in a randomized controlled trial, to report documented response data from each strategy, and to discuss recruitment challenges. METHODS We used 5 opt-in (potential participants have to do something active to contact or be contacted by the researcher) and 2 opt-out (potential participants have the option to decline being contacted a...

Study sample Power calculations were not reported. A sample of 63 patients who underwent emergency CABG was identified and included into the study. There were 10 patients in the MI group and 53 in the CS group. The mean age of the patients was 61.5 (+/11.4) years in the MI group and 61.8 (+/9.4) years in the CS group. The proportions of women in the two groups were 10% (MI) and 34% (CS), respec...

BACKGROUND Maximizing response rates is critically important in order to provide the most generalizable and unbiased research results. High response rates reduce the chance of respondents being systematically different from non-respondents, and thus, reduce the risk of results not truly reflecting the study population. Monetary incentives are often used to improve response rates, but little is ...

OBJECTIVES This study examined sociodemographic, smoking and psychosocial characteristics associated with consent to participate in a smoking cessation trial for socially disadvantaged smokers. DESIGN Baseline data were collected prior to seeking consent for the Call it Quits, a randomised controlled trial. SETTING An Australian social and community service organisation. Sociodemographic, s...

BACKGROUND Response rates for surveys of alcohol use are declining for all modes of administration (postal, telephone, face-to-face). Low response rates may result in estimates that are biased by selective non-response. We examined non-response bias in the NZ GENACIS survey, a postal survey of a random electoral roll sample, with a response rate of 49.5% (n = 1924). Our aim was to estimate the ...

Study sample Power calculations were performed in the preliminary phase of the study. These were based on a 58% success rate for the abdominal group, a 29% success rate for the vaginal group, a significance level of 5% and a statistical power of 80%. This led to a sample size of 40 women in each group, which was increased to 95 to minimise the impact of loss to follow-up (expected to be around ...

Study sample The use of power calculations was not reported. A sample of 502 patients was initially identified. However, of these, 228 did not meet the study criteria, 132 refused to participate, and 96 were excluded because the Clinical Interview Schedule-Revised score was less than 12. Therefore, the final study sample comprised 274 patients. There were 146 patients in the intervention group ...

OBJECTIVE Examine the implications of nonparticipation in studies of treatment adherence among adolescents with chronic health conditions. METHODS Empirical data from an adherence study with adolescents with diabetes were used to demonstrate the influence of family participation on demographic and health outcome variables. Ninety-four families were categorized into one of three groups: (1) fa...