The relationship between size and performance of primary care organisations in England

To examine the relationship between the size and performance of primary care organisations, the effect of and the reasons for mergers.

Data on size, proxy measures of performance and merger intentions for 71 organisations were extracted from telephone and mail surveys of primary care groups and trusts (PCG/Ts).

Of the 22 performance measures examined, only two were significantly associated with size, and over half were not associated with any of the potential explanatory variables. Most organisations (70%) were planning mergers. If all planned mergers take place, the mean size of primary care organisations will double to nearly 200000. The main reasons for mergers were to make better use of resources and for PCGs to become PCTs.

There is little evidence that the performance or efficiency of a primary care organisation is associated with its size. Optimal size may differ for different functions. Mergers are seen as a way of increasing management capacity and may reflect the desire of managers to manage large organisations. There is a risk that larger primary care organisations will recreate hierarchies and lose local ownership and participation.