Study Notes
Study Notes 3305
Study Notes
PUBH3305 1
Study Notes 3305 Recruitment and Retention of Research participants week 5 What is recruitment and retention
Recruitment: communication between researcher and potential participant before consent is given. Generating interest in participating, providing info on study, identifying potential participants. Goals – participants are representative of study population, enough to meet sample size and stat power requirements. Retention: keeping participants in study after they have given consent. Building relationships to encourage continued participation.
The Active Living Study (inc what it is and recruitment plan)
Factors influencing recruitment and retention procedures
Bad recruitment and retention – loss of lime, inc cost, reduced stat power, bias. Active Living Study aimed to examine built and social environmental influences on active living in retirement village residents. Study was initially cross sectional, mixed method after this. Qualitative Phase: village recruitment – 10 retirement villages selected from sampling frame, recruitment materials mailed to village manager, then phone one week later, ended with 6 villages agreeing to have focus groups. Resident recruitment – village contact phoned to make focus group arrangements, recruitment materials mailed to contact to distribute to interested residents, contact phoned to confirm, ended with 51 participants. Quantitative Phase: village recruitment – sampling frame ranked by walkability of neighbourhood, systematically sampled, recruitment materials mailed to village manager (in 3 sets), one week later manager is phoned, 32 villages recruited. Resident recruitment – contact phoned to make arrangements, materials mailed to village contact for random distribution, contact person phoned to confirm arrangements and numbers, 325 participants. Study design, study popn and sample, data collection procedures, research ethics, timeline and budget. With cross sectional studies, as they are only snapshots recruitment may be easier (no follow up commitment). Retention = collecting complete set of data. With case-control studies there is a retrospective comparison between cases and controls, so recruiting representative cases and appropriate controls needs to be done in a way that reduces selection bias. Recruiting controls is hard. Cohort studies are prospective and require larger sample sizes (hard to get) and commitment to follow up (making retention essential). The issues experienced by randomised control trials are similar to cohort studies. People associated with poor response: older adults, males, low SES and education, ethnic minorities. It is easy to overestimate the number of people eligible to participate in a study so selection criteria needs to make results scientifically significant, but not restrict the participant pool too much. Convenience samples are unlikely to be generalisable / representative of the whole population. Need to make sure sample sizes aren’t too big or small (consult biostatician) and that allowances are made in study timeline and budget for recruitment and retention. Types of probability sampling – random, systematic, cluster, stratified. Types of non probability sampling – convenience (man in the street), quote, purposeful, snowball. Response rates – recruitment must be appropriate to generate a response rate that is as high as possible (low response rate = nonresponse bias). Prolonged / lengthy recruitment procedures (such as mail vs telephone vs face-to-face) may challenge recruitment and retention. Researcher must have informed consent, address confidentiality and ethic issues.
2
Study Notes
PUBH3305 1
Study Notes 3305 Recruitment and Retention of Research participants week 5 What is recruitment and retention
Recruitment: communication between researcher and potential participant before consent is given. Generating interest in participating, providing info on study, identifying potential participants. Goals – participants are representative of study population, enough to meet sample size and stat power requirements. Retention: keeping participants in study after they have given consent. Building relationships to encourage continued participation.
The Active Living Study (inc what it is and recruitment plan)
Factors influencing recruitment and retention procedures
Bad recruitment and retention – loss of lime, inc cost, reduced stat power, bias. Active Living Study aimed to examine built and social environmental influences on active living in retirement village residents. Study was initially cross sectional, mixed method after this. Qualitative Phase: village recruitment – 10 retirement villages selected from sampling frame, recruitment materials mailed to village manager, then phone one week later, ended with 6 villages agreeing to have focus groups. Resident recruitment – village contact phoned to make focus group arrangements, recruitment materials mailed to contact to distribute to interested residents, contact phoned to confirm, ended with 51 participants. Quantitative Phase: village recruitment – sampling frame ranked by walkability of neighbourhood, systematically sampled, recruitment materials mailed to village manager (in 3 sets), one week later manager is phoned, 32 villages recruited. Resident recruitment – contact phoned to make arrangements, materials mailed to village contact for random distribution, contact person phoned to confirm arrangements and numbers, 325 participants. Study design, study popn and sample, data collection procedures, research ethics, timeline and budget. With cross sectional studies, as they are only snapshots recruitment may be easier (no follow up commitment). Retention = collecting complete set of data. With case-control studies there is a retrospective comparison between cases and controls, so recruiting representative cases and appropriate controls needs to be done in a way that reduces selection bias. Recruiting controls is hard. Cohort studies are prospective and require larger sample sizes (hard to get) and commitment to follow up (making retention essential). The issues experienced by randomised control trials are similar to cohort studies. People associated with poor response: older adults, males, low SES and education, ethnic minorities. It is easy to overestimate the number of people eligible to participate in a study so selection criteria needs to make results scientifically significant, but not restrict the participant pool too much. Convenience samples are unlikely to be generalisable / representative of the whole population. Need to make sure sample sizes aren’t too big or small (consult biostatician) and that allowances are made in study timeline and budget for recruitment and retention. Types of probability sampling – random, systematic, cluster, stratified. Types of non probability sampling – convenience (man in the street), quote, purposeful, snowball. Response rates – recruitment must be appropriate to generate a response rate that is as high as possible (low response rate = nonresponse bias). Prolonged / lengthy recruitment procedures (such as mail vs telephone vs face-to-face) may challenge recruitment and retention. Researcher must have informed consent, address confidentiality and ethic issues.
2
