Capture-recapture techniques Quick and cheapBMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6927.531 (Published 19 February 1994) Cite this as: BMJ 1994;308:531
- W Gutteridge,
- C Collin
EDITOR, - Capture-recapture techniques can be used as a quick and cheap alternative to population surveys for estimating the prevalence of physical disability.1 We used the technique as part of a needs assessment for a new rehabilitation service. We sent a letter to every general practitioner and district nurse in West Berkshire, requesting the name, age, address, and diagnosis of every patient aged 16 to 65 who had severe disability of neurological, musculoskeletal, or peripheral vascular origin and required daily help from carers or other professional or non-professional helpers. People whose primary disability was mental illness or handicap, blindness, or deafness were excluded.
Altogether 177 (71%) of 249 general practitioners, and district nurses from 42 (76%) of 55 practices, replied. A total of 356 patients were identified (243 by general practitioners alone, 56 by nurses alone, and 57 by both general practitioners and nurses).
A capture-recapture technique2,3 gave the estimated unidentified population as 230. The total population was therefore 594 (95% confidence intervals 494 to 694) and the prevalence 1.9/1000 adults aged 16 to 65.
The main problem with this estimation was that general practitioners and district nurses may have interpreted the definition of severe physical disability inconsistently. Comparison of prevalences estimated in published population surveys is also difficult because of differences in the definition of disability and its severity and in the categorisation of age and underlying disease. But Harris's …