The independent effect of age of general practitioner on clinical practice

General practice style is influenced by age, qualifications and sex of practitioner, and patient population. Researchers in Canada found a link between physicians’ age and quality of care,1 and recent Australian research showed an association between age and length of consultation.2

A 2004 study found that the Australian general practice workforce aged significantly between 1991 and 2003,3 and as there are now more general practitioner registrar positions than there are applicants for training,4,5 the trend towards an older GP workforce is likely to continue. Continuity of care is important to patients,6,7 and a high percentage remain with their chosen GP over time,8,9 so patients often grow older with their GP, and there is evidence that patient population influences practice style.10 Change over time in medical education is another factor.11,12

Given these trends, we can assume that newcomers to the general practice workforce will possess similar characteristics to the younger GPs currently practising, but it is difficult to predict how much that will influence their style as they and their patients age. One study found that young GPs’ antibiotic prescribing patterns gradually converge towards the mean,13 and another found remarkable consistency in diagnostic recording over time.10

A recent systematic review of studies that included length of time in medical practice and quality of care found that increasing practitioner experience often had a negative effect on performance.14 Trends in hypertension management,15 standards of care for diabetes mellitus,16 adoption of new procedures,17 and inappropriate prescribing18 were among the topics examined.

We sought to isolate GP age from other measurable factors and examine its independent effect on practice method and the patient encounter. We used data from a quarter of the practising GP population in Australia to compare those from different age groups for their characteristics, their patient clusters, and the morbidity they managed.19

This is a secondary analysis of data from the BEACH (Bettering the Evaluation and Care of Health) program, a continuous national study of general practice activity in Australia.19 In brief, about 20 different GPs participate per week, each recording details of 100 consecutive doctor–patient encounters. They also provide their demographic and practice characteristics. Data from April 1998 to March 2003, provided by 5013 GPs, were used. Participating GPs were divided into five age groups for analysis. Problems managed were classified according to the International Classification of Primary Care, version 2 (ICPC-2).20

The association between the number of years in general practice and age of GP yielded a high correlation (r = 0.89, P < 0.001), confirming reports by other researchers.18 For this study, the two variables can be considered interchangeable.

An extensive literature review suggests this is the first large-scale study that specifically measures GP age alone, and with its sample size we can generalise results to the total GP population. It demonstrates that certain clinical actions are clearly related to GP age, after the influence of measured confounding factors are removed. That young GPs are more often female and hold FRACGP were two of the factors taken into account in the regression model. Age of patient was controlled for, as GPs attract patients close to their own age, affecting the morbidity managed. This in turn influences the treatments they choose, so we also adjusted for morbidity when examining treatment patterns.

Choudhry et al discussed the need for specific research into the association between length of time in practice and performance.14 Our study addresses this issue by presenting a comprehensive view of the influence of GP age on the patient–doctor encounter. Most of the studies in the review by Choudhry et al focused on a single aspect or disease, 40% of them were published more than 10 years ago, and many of the study samples were self-selected. We report recent data from a large, representative, random sample, and investigated multiple outcome measures.

However, our study is limited to the quantifiable details of GP encounters; intangible attributes such as manner of dealing with patients or diagnostic expertise are not measured. We are also limited to describing the current situation, although we surmise that, in the foreseeable future, assuming no major changes occur in policy or education, new graduates will have similar traits to the younger GPs in this study.

Younger GPs prescribing less and using more non-pharmacological treatments would be a long-term cost-saving element for the Australian Government only if they retain these habits as they age. In contrast, their high pathology ordering would lead to increased costs to government if they continue to order at this rate. One study found that an intervention group maintained their antibiotic prescribing behaviour after 5 years,13 but by then the control group had acquired the same habits. This suggests that age, sex and training of young GPs are more influential than the effects of educational interventions.

The extensive use of non-pharmacological treatments (mainly advice and counselling) by young GPs and the high prescribing rates of older GPs could not be explained by patient mix or other GP characteristics. The high pathology ordering rates among young GPs may reflect their lower management rates of chronic problems, which might place them more often on an investigative pathway. Alternatively, it may reflect differences in levels of experience or fear of litigation. Perhaps with increased years in general practice they will test less often.

In problem management, several of the adjusted results were consistent with the univariate findings, indicating that age of GP alone was responsible for the differences. This could be seen in the management of circulatory, respiratory, skin, neurological and psychological problems. On the other hand, some descriptive findings disappeared after adjustment, particularly those that are clearly linked to patient characteristics, pointing to the high correlation between age of GP and age and sex of patient.

Our study provides solid evidence of the connection between practitioner experience and practice style, against which the link between experience and quality of care can be further considered. It provides a background for medical educators and those providing support and information to GPs during their careers. It is also relevant to issues of workforce planning, not just for general practice, but for other branches of medicine.