Should performance indicators in general practice relate to whole practices or to individual doctors?

In a study of referrals to East Anglian hospitals 737 referrals in six specialties from three general practices were examined to see how accurately the hospital computer master index had identified the referring practice, the referring general practitioner and the doctor with whom the patient was registered. Although the practice was accurately identified by the hospital computer in 97% of referrals, the identification of the referring doctor and the patient's registered general practitioner were less reliable (72% and 49% respectively). It is concluded that at present the practice rather than the individual doctor may be the appropriate unit of analysis for studies of general practitioners' referral rates. This may be true for other performance indicators where information on a doctor's case mix and workload is not available. The results of this study emphasize that problems may arise if data relating to individual general practitioners are interpreted out of context of the practice and the way in which it is organized.