Objectives: To analyse the variability of certain indicators of the procedure and outcome of medical care in the clinical records of diabetic and hypertense patients, and their relationship with the doctor's style of practice.
Design: An observational, descriptive study.
Setting: Seven health centres in the public network.
Participants: 40 primary care doctors (all the doctors).
Measurements and main results: By means of stratified systematic random sampling, 20 clinical histories for each doctor were chosen (10 for patients diagnosed with diabetes mellitus and 10 with hypertension). The deviation ratio was used as the measurement of variability. Doctors' styles of medical practice were evaluated through the Australia questionnaire. Great variability was found in the frequency with which the different indicators of the two pathologies were recorded (deviation ratio: weight > 90.02% in DM, 81.37% in HT; height > 84.01% in DM, 77.10% in HT), and in the absolute figures (patients with HT, wide variability in all outcome indicators; patients with DM, in last figures, total and HDL cholesterol, and HbA1c). The styles of practice were shown to be related to the frequency of appearance of some indicators in the clinical records and with the quality of particular outcome indicators. The age of the doctor correlated significantly, and negatively, with the recording of almost all the indicators and their quality.
Conclusions: Variability of medical practice in the care of the chronically ill seen in primary care does exist. The use of clinical practice guides is emphasised.