Characteristics of trials and participants
| Characteristics | Blood pressure (BP) difference trials | Drug class comparison trials | All trials | ||
| BP-lowering intensity | Placebo controlled | All BP difference trials | |||
| Trials | |||||
| No. of trials | 9 | 21 | 30 | 29 | 52* |
| No. of trials by year of end of study | |||||
| Before 1990 | 1 | 2 | 3 | 0 | 3 |
| 1990–1999 | 2 | 7 | 9 | 7 | 14 |
| 2000–2009 | 2 | 10 | 12 | 19 | 27 |
| After 2009 | 4 | 2 | 6 | 3 | 8 |
| Mean (SD) trial duration (years) | 4 (2) | 4 (2) | 4 (2) | 4 (2) | 4 (2) |
| Mean (median) no. of follow-up BP measures | 14 (13) | 7 (6) | 8 (8) | 8 (7) | 8 (8) |
| Participants | |||||
| No. of participants (% women) | 35 934 (45) | 112 934 (35) | 148 873 (38) | 224 038 (44) | 363 684 (42) |
| % (n/N) Caucasian/European ethnicity | 46 (15 863/34 823) | 68 (58 851/86 908) | 61 (74 714/121 731) | 64 (118 128/185 351) | 63 (188 948/297 852) |
| % (N) current smoker at baselineb | 22 (8238/35 908) | 16 (17 702/111 190) | 18 (25 940/147 098) | 20 (44 173/220 708) | 19 (68 360/359 719) |
| Mean (SD) baseline SBP/DBP | 151 (21)/88 (15) | 146 (21)/83 (11) | 147 (21)/84 (12) | 156 (21)/90 (12) | 152 (21)/87 (12) |
| % (N) participants by baseline SBP (mm Hg) | |||||
| <120/<70 | 4 (2870)/11 (3806) | 8 (9176)/9 (10 037) | 7 (10 650)/9 (13 843) | 3 (7027)/5 (10 410) | 5 (17 128)/7 (23 803) |
| 120–129/70–79 | 9 (6228) / 17 (6075) | 13 (15 063)/24 (26 927) | 13 (18 448)/22 (33 002) | 6 (12 969)/14 (31 330) | 9 (30 720)/17 (63 091) |
| 130–139/80–89 | 18 (11,289) / 24 (8593) | 17 (19 674)/39 (43 738) | 18 (26 077)/34 (50 623) | 11 (23 906)/28 (62 292) | 14 (48 820)/30 (109 589) |
| 140–149/90–99 | 19 (11 393)/29 (14 890) | 18 (20 590)/21 (24 043) | 19 (27 386)/23 (34 324) | 18 (41 220)/30 (67 403) | 19 (66 928)/27 (98 994) |
| 150–159/100–109 | 17 (10 050)/14 (6342) | 14 (16 246)/7 (7355) | 14 (21 107)/8 (12 264) | 19 (42 509)/18 (39 839) | 17 (61 495)/14 (51 014) |
| ≥160/≥110 | 33 (19 050)/6 (2696) | 28 (32 114)/1 (750) | 30 (43 396)/2 (2994) | 43 (95 833)/5 (12 188) | 38 (136 226)/4 (14 810) |
| Mean (SD) age (years) at baseline | 61 (12) | 65 (10) | 64 (11) | 65 (9) | 65 (10) |
| % (N) of participants by age at baseline | |||||
| <50 years | 16 (7146) | 5 (5596) | 8 (11 256) | 4 (9542) | 5 (19 122) |
| 50–59 years | 34 (18 465) | 22 (24 668) | 25 (36 978) | 24 (52 819) | 24 (86 699) |
| 60–69 years | 27 (18 005) | 39 (44 374) | 36 (54 016) | 39 (87 144) | 38 (137 849) |
| 70–79 years | 18 (13 313) | 26 (28 921) | 24 (35 264) | 28 (63 119) | 27 (97 290) |
| ≥80 years | 6 (3999) | 8 (9342) | 8 (11 321) | 5 (11 369) | 6 (22 638) |
| % (N) with condition at baseline† | |||||
| Cardiovascular disease | 16 (5617/35 934) | 66 (72 209/110 020) | 54 (78 738/145 945) | 45 (98 944/221 993) | 49 (175 519/359 357) |
| Coronary heart disease | 11 (4120/35 934) | 41 (45 591/110 008) | 34 (49 711/145 942) | 38 (67 766/177 363) | 37 (115 562/316 125) |
| Stroke | 3 (966/34,840) | 34 (32 650/95 800) | 28 (36 521/130 643) | 11 (17 830/168 003) | 18 (51 320/292 559) |
| Diabetes | 24 (8540/35 934) | 36 (36 179/100 697) | 33 (44 719/136 631) | 26 (58 404/223 654) | 28 (99 375/351 357) |
| Chronic kidney disease | 33 (4854/14 799) | 9 (2845/25 789) | 19 (7699/40 588) | 17 (18 917/108 612) | 17 (24 289/145 895) |
| % (N) previously on BP-lowering medication† | 34 (12 141/35 934) | 71 (73 833/103 766) | 65 (73 237/126 502) | 77 (119 454/155 069) | 69 (202 428/293281) |
| Mean (SD) body mass index† (kg/m2) | 29 (6) | 28 (5) | 28 (5) | 28 (5) | 28 (5) |
*Some trials provided data to more than one trial design.
†Data limited to those with relevant information and N refers to the denominator for number of participants with information on the relevant variable.
SBP, systolic blood pressure; DBP, diastolic blood pressure.