Box 3.

: Effects of population size and organisational features on primary care organisations' performance

• Direct provision of services may improve control, but commissioning services provides increased flexibility and can achieve high levels of integration
• Larger primary care groups and trusts are likely to become more centralised and hierarchical with less professional engagement
• Partnerships and alliances around particular functions may have advantages over a single size for all functions
• Mergers often fail to deliver the anticipated benefits
• Positive outcomes of mergers require substantial investment in the management of change and may damage staff morale