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Centre for Policy on Ageing | |
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| Random versus volunteer selection for a community-based study | | Author(s) | Mary Ganguli, Mary E Lytle, Maureen D Reynolds |
| Journal title | The Journals of Gerontology Series A: Biological sciences and medical sciences, vol 53A, no 1, January 1998 |
| Pages | pp M39-M46 |
| Keywords | Health [elderly] ; Living in the community ; Sampling ; Methodology ; Cross sectional surveys ; United States of America. |
| Annotation | The effects of selection factors when recruiting subjects into studies can introduce bias and seriously limit the applicability of results. For an epidemiological study, an age-stratified random sample of 1,422 community-dwelling over 65s was recruited from the voter registration lists in a rural area of south-western Pennsylvania, the first 1,366 obtained through intensive recruitment efforts, and the last 56 responding to a single mailing. To increase sample size for future risk analyses, a sample of 259 volunteers from the same area was recruited by direct advertisement. The three groups were compared on selected baseline characteristics and subsequent mortality. The two sub-groups of the random sample were not significantly different on any of the variables examined. Compared to the random sample, volunteers were significantly more likely to be women, more educated, and have used fewer health services. Volunteers also had higher cognitive test scores and instrumental activities of daily living (IADL) ability. Over 6-8 years of follow-up, volunteers had significantly lower mortality rates than randomly selected subjects. Care should be taken to avoid volunteer bias in health-related studies. (RH). |
| Accession Number | CPA-980310415 A |
| Classmark | CC: K4: 3Y7: 3D: 3KB: 7T |
Data © Centre for Policy on Ageing |
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| ...from the Ageinfo database published by Centre for Policy on Ageing. |
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