Table 1

Summary of the characteristics of the included studies

Disease conditionInterventionsSettingRCT outcomesCost considerations (Y/N/NA)
20 studies on depression.Interventions mostly around collaborative care through increasing expertise of different roles (eg, lay worker, nurse for proactive care, GP for PHC) (16 studies), times to implement practice guidelines (4 studies), and trialling specific interventions such as physical exercise and cognitive–behavioural therapy (2 studies).9 UK.
7 USA.
1 Sweden.
1 Germany.
1 Australia.
1 India.
11 Positive .
5 Negative.
4 NA.
4 Y.
14 N.
2 NA.
17 studies on diabetes.The interventions included improving guideline-based referral and treatment (7 studies), patient self-management, community support (7 studies) and telehealth (3 studies).4 Ireland.
3 UK.
1 Norway.
3 USA
2 Canada (1 of the First Nations).
2 Australia.
1 New Zealand.
1 Malaysia.
6 Positive.
10 Negative.
1 NA.
3Y.
13 N.
1 NA.
25 studies on CVD.10 studies were about improving the screening and management of CVD using best-practice guidelines (eg, educational materials to improve referral or decision analysis). 10 studies were about organisational change with models of care that incorporated new roles such as a nurse-led clinic, or the use of a lay worker for angina management, and technology (eg, telemonitoring, point of care testing). 5 studies explored trial implementation such as recruitment of patients and providers, and were less about the intervention.9 UK.
6 Australia.
3 Canada.
2 New Zealand.
2 The Netherlands.
1 Ireland.
1 USA.
1 Zambia.
15 Positive.
5 Negative.
5 NA.
3 Y.
15 N.
6 NA.
6 studies on COPD (2 including other chronic disease) and 1 addressing CKD.4 studies were about improving self-management of patients through educational materials, or use of monitoring, with support from health providers. 2 studies were about stimulating physical activity through the use of technology. 1 study was about implementing management guidelines in CKD in PHC.3 The Netherlands.
1 Ireland.
1 UK (Scotland).
1 USA.
1 Australia.
2 Positive.
1 Negative.
4 NA.
0 Y.
5 N.
2 NA.
Overall synthesis of 69 studies in total.
20 depression, 17 diabetes, 25 CVD, 6 COPD and 1 CKD.
Overall, the complex primary care interventions fit within the general categories of facilitating patient self-management (13 studies), organisational change to include collaborative care (16 studies), facilitating better case management using clinical information systems (eg, telehealth) (15 studies), and the use of decision support and guideline implementation (eg, referral systems) (22 studies). In addition, 5 studies were exploring the conduct of trials in PHC, for example, the recruitment of patients.22 UK.
10 Australia.
12 USA.
6 Ireland.
5 The Netherlands.
5 Canada.
3 New Zealand.
1 Sweden.
1 Germany.
1 India.
1 Norway.
1 Malaysia.
1 Zambia.
In addition, 2 studies focused on First Nations peoples in Australia and in Canada. 3 studies were focused on the populations living in disadvantage.
34 Positive.
21 Negative.
14 NA.
10 Y*.
48 N.
11 NA.
  • *Of note two were full evaluation reports (outcome, process and economic evaluations) in the UK journal of Health Technology Assessments in addressing the question of whether an innovation with limited evidence base in a pragmatic setting (eg, introducing cognitive–behavioural therapy in schools) should be scaled up. Eight papers included descriptions of how cost considerations such as financing incentives/government subsidies impacted on intervention implementation.

  • CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; GP, general practices; N, no; NA, not applicable; PHC, primary healthcare; RCT, randomised controlled trial; Y, yes.