RT Journal Article SR Electronic T1 Matched controls in surveys of the use of general practice JF The Journal of the Royal College of General Practitioners JO J R Coll Gen Pract FD British Journal of General Practice SP 801 OP 810 VO 25 IS 160 A1 Ian Russell YR 1975 UL http://bjgp.org/content/25/160/801.abstract AB This paper describes how an age-sex register may be used as a sampling frame for the selection of matched controls in studies of the use of general practice. It discusses both the analysis of data collected in this way and the advantages and limitations of the method itself. The application of the method to a case-study suggests that patients who use hospital accident departments are also high users of general practice. Although care is needed in the interpretation of such results, it is concluded that matched controls can be used to ameliorate some of the problems of research in general practice.