Table 3.
Point estimates for risk of two study outcomes. Cumulative risk and time-to-event models are shown, each with several methods of covariate adjustment. Models (3) and (4) include the same covariate set—(3) as individual covariates and (4) as components of the propensity score—and should therefore yield substantially similar estimates
| Outcome | Within-center analyses |
Combined Center Analyses |
|||||
|---|---|---|---|---|---|---|---|
| British Columbia† (n = 19 979) | Pennsylvania (n = 4176) | New Jersey (n = 3998) | Horizon (n = 3451) | Pooled‡ (n = 31 604) | Meta-analysis§ |
||
| Fixed-effects estimate (n = 31 604) | p-value for heterogeneity among centers | ||||||
| Myocardial infarction hospitalization | |||||||
| Cumulative risk analysis (odds ratios) | |||||||
| Number of events (risk) among PPI users | 135 (6.2%) | 48 (3.6%) | 41 (3.2%) | 21 (2.6%) | 245 (4.3%) | — | — |
| Number of events (risk) among non-users | 669 (3.8%) | 85 (3.0%) | 64 (2.4%) | 46 (1.7%) | 864 (3.3%) | — | — |
| 1 Crude | 1.68 [1.39, 2.03] | 1.19 [0.83, 1.70] | 1.35 [0.91, 2.02] | ~1.47 [0.87, 2.48] | 1.52 [1.30, 1.76] | 1.52 [1.31, 1.76] | 0.36 |
| 2 Adjusted by shareable variables | 1.50 [1.23, 1.81] | 1.20 [0.84, 1.73] | 1.31 [0.88, 1.95] | ~1.42 [0.84, 2.40] | 1.40 [1.21, 1.63] | 1.41 [1.21, 1.64] | 0.75 |
| 3 Adjusted by shareable and private variables | 1.23 [1.00, 1.52] | 1.18 [0.80, 1.72] | ~1.21 [0.79, 1.86] | ~1.05 [0.60, 1.86] | 1.20 [1.03, 1.41] | 1.20 [1.03, 1.41] | 0.96 |
| 4 Adjusted by universal PS | 1.23 [1.01, 1.50] | 1.19 [0.82, 1.74] | 1.14 [0.75, 1.71] | ~1.11 [0.65, 1.91] | 1.16 [1.00, 1.36] | 1.20 [1.03, 1.40] | 0.98 |
| 5 Adjusted by hd-PS | 1.15 [0.94, 1.41] | 1.03 [0.69, 1.56] | 1.27 [0.82, 1.98] | ~0.99 [0.55, 1.78] | 1.11 [0.95, 1.31] | 1.14 [0.97, 1.33] | 0.88 |
| Time-to-event analysis (hazard ratios) | |||||||
| 1 Crude | 1.87 [1.49, 2.35] | 2.03 [1.16, 3.56] | 1.32 [0.74, 2.36] | 1.21 [0.62, 2.33] | 1.74 [1.44, 2.11] | 1.75 [1.45, 2.12] | 0.44 |
| 2 Adjusted by shareable variables | 1.66 [1.32, 2.09] | 2.12 [1.21, 3.71] | 1.25 [0.70, 2.22] | 1.18 [0.61, 2.27] | 1.60 [1.32, 1.94] | 1.61 [1.33, 1.95] | 0.45 |
| 3 Adjusted by shareable and private variables | 1.34 [1.06, 1.71] | 1.99 [1.11, 3.56] | 1.19 [0.65, 2.17] | 0.75 [0.37, 1.54] | 1.34 [1.10, 1.63] | 1.33 [1.09, 1.62] | 0.22 |
| 4 Adjusted by decile of universal PS | 1.35 [1.07, 1.71] | 2.11 [1.16, 3.81] | 1.22 [0.67, 2.21] | 0.88 [0.45, 1.72] | 1.32 [1.09, 1.61] | 1.35 [1.11, 1.64] | 0.28 |
| 5 Adjusted by decile of hd-PS | 1.28 [1.00, 1.63] | 1.95 [1.03, 3.70] | 1.05 [0.56, 1.98] | 0.78 [0.38, 1.59] | 1.22 [0.99, 1.50] | 1.25 [1.02, 1.54] | 0.28 |
| Hospitalization for revascularization | |||||||
| Cumulative risk analysis (odds ratios) | |||||||
| Number of events (risk) among PPI users | 105 (4.8%) | 96 (7.1%) | 114 (8.8%) | 106 (12.9%) | 421 (7.4%) | — | |
| Number of events (risk) among non-users | 661 (3.7%) | 192 (6.8%) | 259 (9.6%) | 255 (9.7%) | 1367 (5.3%) | — | |
| 1 Crude | 1.30 [1.06, 1.61] | 1.05 [0.81, 1.35] | 0.92 [0.73, 1.15] | ~1.38 [1.08, 1.75] | 1.15 [1.02, 1.29] | 1.15[1.03, 1.30] | 0.05 |
| 2 Adjusted by shareable variables | 1.35 [1.09, 1.67] | 1.05 [0.81, 1.35] | 0.94 [0.74, 1.18] | ~1.38 [1.08, 1.76] | 1.17 [1.04, 1.32] | 1.17 [1.04, 1.32] | 0.05 |
| 3 Adjusted by shareable and private variables | 1.23 [0.99, 1.53] | 1.02 [0.78, 1.34] | 0.96 [0.75, 1.22] | ~1.39 [1.09, 1.79] | 1.15 [1.02, 1.30] | 1.14 [1.01, 1.29] | 0.13 |
| 4 Adjusted by universal PS | 1.27 [1.02, 1.57] | 1.03 [0.79, 1.35] | 0.94 [0.74, 1.20] | ~1.38 [1.07, 1.77] | 1.13 [1.00, 1.28] | 1.15 [1.02, 1.30] | 0.11 |
| 5 Adjusted by hd-PS | 1.21 [0.97, 1.50] | 1.07 [0.81, 1.43] | 0.88 [0.68, 1.14] | ~1.31 [1.00, 1.71] | 1.07 [0.94, 1.21] | 1.11 [0.98, 1.26] | 0.16 |
| Time-to-event analysis (hazard ratios) | |||||||
| 1 Crude | 1.41 [1.08, 1.32] | 0.96 [0.67, 1.37] | 0.77 [0.56, 1.05] | 1.34 [1.02, 1.77] | 1.12 [0.96, 1.30] | 1.14 [0.98, 1.32] | 0.01 |
| 2 Adjusted by shareable variables | 1.50 [1.15, 1.96] | 0.95 [0.66, 1.36] | 0.78 [0.57, 1.06] | 1.34 [1.02, 1.77] | 1.14 [0.98, 1.32] | 1.16 [1.00, 1.35] | 0.01 |
| 3 Adjusted by shareable and private variables | 1.42 [1.08, 1.87] | 0.96 [0.66, 1.39] | 0.78 [0.56, 1.07] | 1.34 [1.01, 1.78] | 1.14 [0.97, 1.32] | 1.14 [0.98, 1.33] | 0.02 |
| 4 Adjusted by universal PS | 1.44 [1.10, 1.88] | 0.93 [0.64, 1.36] | 0.76 [0.55, 1.05] | 1.32 [0.99, 1.75] | 1.11 [0.95, 1.29] | 1.13 [0.97, 1.32] | 0.01 |
| 5 Adjusted by hd-PS | 1.41 [1.07, 1.86] | 0.92 [0.62, 1.38] | 0.70 [0.50, 0.99] | 1.30 [0.96, 1.77] | 1.07 [0.91, 1.26] | 1.10 [0.94, 1.30] | 0.01 |
PS Propensity score; hd-PS High dimensional propensity score. Universal PS included all shareable and private variables.
PS-adjusted models are adjusted by indicators for decile of PS. PS deciles are computed within each center.
Model failed to converge and value is approximate.
Within-center odds ratios are estimated by logistic regression.
Pooled odds ratios are estimated by conditional logisitic regression. Pooled hazard ratios are estimated by Cox proportional hazards models. Both are stratified by center.
Fixed-effects meta-analysis method. The random effects method yielded nearly identical results which are not displayed.