Table 2

Study and patient characteristics

CharacteristicResult
Patient RCTs, n (%)94 (66.2)
Cluster RCTs, n (%)48 (33.8)
Number of clusters, median (IQR)29 (12, 57)
Number of patients, median (IQR)405.3 (203, 878)
Duration of intervention months, median (IQR)12 (8.9, 15.0)
Mean age in years, median (IQR)59.4 (54.9, 62.9)
Percentage of male, median (IQR)49.8 (41.8, 55.9)
Type of diabetes n (%)
 Type 1 diabetes9 (6.3)
 Type 2 diabetes80 (56.3)
 Type 1 and 2 diabetes34 (23.9)
 Type of diabetes unclear/NR19 (13.4)
Number of QIs per RCT median (IQR)2 (0, 3.5)
Administrators of patient intervention(s), n (%)
 Primary care physician30 (21.1)
 Nurse67 (47.2)
 Pharmacist19 (13.4)
 Dietician22 (15.5)
 Psychiatrist3 (2.1)
 Psychologist2 (1.4)
 Ophthalmologist2 (1.4)
 Specialist/endocrinologist21 (14.8)
 Other49 (34.5)
Location of study, n (%)
 The USA68 (47.9)
 The UK14 (9.9)
 Canada11 (7.7)
 The Netherlands8 (5.6)
 South Korea7 (4.9)
 Australia6 (4.2)
 Denmark3 (2.1)
 Belgium1 (0.7)
 Israel3 (2.1)
 Spain3 (2.1)
 Norway2 (1.4)
 France2 (1.4)
 Germany2 (1.4)
 Italy2 (1.4)
 Switzerland2 (1.4)
 China2 (1.4)
 Ireland1 (0.7)
 New Zealand1 (0.7)
 Thailand1 (0.7)
 Taiwan1 (0.7)
 United Arab Emirates1 (0.7)
 Mexico1 (0.7)
  • All IQRs reported as the 25th and 75th percentiles, includes investigators and community workers.

  • N, number; NA, not applicable; NR, not reported; QI, quality improvement; RCT, randomised clinical trial.