Table 1 Study characteristics in cohort studies reporting and not reporting HTE
From: Reporting of heterogeneity of treatment effect in cohort studies: a review of the literature
Study characteristics | All studies (n = 150) | Studies addressing HTE (n = 88) | Studies not addressing HTE (n = 62) | p-value | Studies addressing HTEa,* (n = 111) |
|---|---|---|---|---|---|
Sample size, Med(Q1-Q3) | 1633(310–9505) | 3754(850–20,474) | 470(130–2210) | <0.001 | 1235(201–6133) |
Length of follow up (years), Med(Q1-Q3) | 3.5(1.2–7.2) | 5(2–10) | 2(0.5–4.2) | <0.001 | 3(1–6) |
Date of publication | 0.04 | ||||
2000–2013 | 72(48) | 47(53.4) | 23(37) | 52(47) | |
2014–2016 | 78(52) | 41(46.6) | 39(63) | 59(53) | |
Journal type, n(%) | <0.001 | ||||
High impact factor journals (HIJ) | 75(50) | 55(62.5) | 20(32.2) | 52(47) | |
Low impact factor journals (LIJ) | 75(50) | 33(37.5) | 42(67.8) | 59(53) | |
Source of funding, n(%) | 0.85 | ||||
Industry | 100(66.7) | 62(70.5) | 38(61.3) | 69(62) | |
Other | 31(20.7) | 19(21.6) | 10(16.1) | 22(20) | |
NA | 19(12.6) | 7(8) | 14(22.6) | 20(18) | |
Study area, n(%) | <0.001 | ||||
Interventional | 50(32.7) | 19(21.6) | 31(50) | 54(49) | |
Pharmacological | 89(60) | 64(72.7) | 25(40.3) | 56(50) | |
Other | 11(7.3) | 5(5.7) | 6(9.7) | 1(1) | |
Type of primary outcome, n(%) | 0.004 | ||||
Time to event | 65(44) | 48(54.5) | 17(27.4) | 46(41) | |
Binary | 50(32.7) | 24(27.3) | 26(42) | 37(33) | |
Continuous | 35(22) | 16(18.2) | 19(30.6) | 28(26) | |
Main effect of primary outcome, n(%) | 0.6 | ||||
Statistically significant | 96(64.6) | 58(65.9) | 38(61.3) | 69(62) | |
Not statistically significant | 54(35.4) | 30(34.1) | 24(38.7) | 42(38) | |
Newcastle-Ottawa Quality Assessment Score, n(%) | 0.82 | ||||
0–3 | 5(3) | 3(3) | 2(3) | 3(3) | |
4–6 | 88(59) | 54(61) | 34(55) | 64(58) | |
7–8 | 57(38) | 31(35) | 26(29) | 44(40) | |
HTE reporting | 88(58.7) | 88(100) | – | 49(44) | |
Analysis of predictive factors on side effects, n(%) | 2(1.3) | 2(2.3) | – | 2(2) | |
Prespecification of HTE analysis, n(%) | 84(56) | 84(95.4) | – | 46(94) | |
Type of HTE analysis, n(%) | |||||
Subgroup | 2(1.3) | 2(2.3) | – | 2(4) | |
Adjusted | 67(44.7) | 67(76.1) | – | 34(69) | |
Propension | 19(12.7) | 19(21.6) | – | 13(27) | |
Predictive variables studied, n(%) | |||||
Age | 30(20) | 30(34) | – | 30(61) | |
Sexe | 15(10) | 15(17) | – | 15(31) | |
Social level | 4(2.7) | 4(4.5) | – | 4(8) | |
Genetics | 12(8) | 12(13.6) | – | 12(24) | |
Treatment | 66(44) | 66(75) | – | 27(55) | |
Comorbidities | 31(20.7) | 31(35) | – | 31(63) | |
Severity of disease | 13(8.7) | 13(14.7) | – | 13(26) | |
Prognostic variables studied, n(%) | 51(34) | 31(35.2) | 20(3.2) | 0.73 | 31(28) |
Analysis of prognostic factors on side effect, n(%) | 2(1.3) | 1(1.1) | 1(1.6) | 0.71 | 1(1) |
Interaction test, n(%) | 27(18) | 27(31) | 0(0) | – | 8(7) |