Does practice size matter? Review of effects on quality of care in primary care

There is a trend towards consolidating smaller primary care practices into larger practices worldwide. However, the effects of practice size on quality of care remain unclear.

This review aims to systematically appraise the effects of practice size on the quality of care in primary care.

A systematic review and narrative synthesis of studies examining the relationship between practice size and quality of care in primary care.

Quantitative studies that focused on primary care practices or practitioners were identified through PubMed, CINAHL, Embase, Cochrane Library, CRD databases, ProQuest dissertations and theses, conference proceedings, and MedNar databases, as well as the reference lists of included studies. Independent variables were team or list size; outcome variables were measures of clinical processes, clinical outcomes, or patient-reported outcomes. A narrative synthesis of the results was conducted.

The database search yielded 371 articles, of which 34 underwent quality assessment, and 17 articles (13 cross-sectional studies) were included. Ten studies examined the association of practice size and clinical processes, but only five found associations of larger practices with selected process measures such as higher specialist referral rates, better adherence to guidelines, higher mammography rates, and better monitoring of haemoglobin A1c. There were mixed results for cytology and pneumococcal coverage. Only one of two studies on clinical outcomes found an effect of larger practices on lower random haemoglobin A1 value. Of the three studies on patient-reported outcomes, smaller practices were consistently found to be associated with satisfaction with access, but evidence was inconsistent for other patient-reported outcomes evaluated.

There is limited evidence to support an association between practice size and quality of care in primary care.