Bulletin of the World Health Organization

Use of data from registered clinical trials to identify gaps in health research and development

Roderik F Viergever, Robert F Terry & Ghassan Karam

Volume 91, Number 6, June 2013, 416-425C

Table 3. Areas of recruitment for the actively recruiting, interventional trials registered in the International Clinical Trials Registry Platform (ICTRP), 2012

Area of recruitment No. of trials in samplea Estimate
Percentage (95% CI) of trials in ICTRPb No. (95% CI) of trials in ICTRP
Total Per 1 000 000 inhabitants Per 1 000 000 DALYs
World Bank income group21
High-income country 2115 89.0 (87.7–90.2) 42 300 (41 671–42 869) 37.2 (36.7–37.7) 292.7 (288.4–296.7)
Upper-middle-income country 292 12.3 (11.0–13.7) 5840 (5241–6496) 2.4 (2.1–2.6) 13.4 (12.0–14.9)
Lower-middle-income country 111 4.7 (3.9–5.6) 2220 (1850–2659) 0.9 (0.7–1.0) 3.0 (2.5–3.6)
Low-income country 14 0.6 (0.4–1.0) 280 (167–469) 0.3 (0.2–0.6) 0.8 (0.5–1.3)
WHO region22
Africa 50 2.1 (1.6–2.8) 1000 (760–1313) 1.1 (0.9–1.5) 2.2 (1.7–2.9)
Americas 840 35.3 (33.4–37.3) 16 800 (15 898–17 724) 17.7 (16.7–18.7) 107.9 (102.1–113.8)
Eastern Mediterranean 65 2.7 (2.2–3.5) 1300 (1023–1650) 2.1 (1.6–2.6) 7.6 (6.0–9.7)
Europe 1055 44.4 (42.4–46.4) 21 100 (20 156-22 053) 23.4 (22.3–24.4) 136.3 (130.2–142.5)
South-East Asia 96 4.0 (3.3–4.9) 1920 (1578–2333) 1.0 (0.9–1.3) 3.9 (3.2–4.8)
Western Pacific 548 23.1 (21.4–24.8) 10 960 (10 176-11 785) 6.0 (5.6–6.5) 39.7 (36.8–42.6)

CI, confidence interval; DALY, disability-adjusted life year; WHO, World Health Organization.

a Estimated percentages and numbers for the whole ICTRP were based on the results of the analysis of the records for a 5% sample of the trials registered on the platform.

b The percentages shown are those of the 2377 trials in the sample for which the country or countries of recruitment could be determined from the registered records. When summed, the percentages shown for income groups or regions exceed 100% because some trials were recruiting in multiple countries belonging to more than one income group or region.