Table 3.
Hazard ratio of lactic acidosis for metformin by CLD/CKD
| Variables | Main cohort (before matching)* | Main cohort adjusted by propensity score (20 strata)† | Propensity score‐matched cohort‡ |
|---|---|---|---|
| Number of LA cases | 30 | 30 | 10 |
| Non metformin users | 23 | 23 | 5 |
| Metformin users | 7 | 7 | 5 |
| Hazard ratio | |||
| Non metformin users | Ref | Ref | Ref |
| Metformin users | 0.92 [0.33–2.55] | 0.89 [0.32–2.49] | 0.90 [0.26–3.11] |
| Age ≥ 75 y | 1.67 [0.79–3.53] | 1.36 [0.61–3.04] | 2.02 [0.41–9.09] |
| Female | 1.03 [0.49–2.17] | 1.10 [0.52–2.30] | 1.05 [0.29–3.77] |
| Duration of metformin use before cohort entry (day) | 1.00 [1.00–1.01] | 1.00 [1.00–1.01] | 1.01 [1.00–1.01] |
| Insulin | 1.64 [0.76–3.51] | — | 2.85 [0.31–26.39] |
| Hypertension | 1.26 [0.54–2.89] | — | 1.03 [0.21–5.10] |
| Ischemic heart disease | 1.11 [0.42–2.89] | — | 0.96 [0.83–1.10] |
| Heart failure | 2.37 [0.98–5.75] | 2.39 [1.00–5.71] | — |
| Complications of diabetes | 1.73 [0.78–3.84] | 1.94 [0.90–4.19] | 2.58 [0.67–10.01] |
| Dyslipidemia | — | — | 0.48 [0.06–3.81] |
| Cerebrovascular disease | — | — | 1.65 [0.20–13.73] |
| Gastric ulcer | 2.05 [0.86–4.93] | — | 1.64 [0.20–13.79] |
| Chronic liver disease | 1.44 [0.65–3.17] | 1.42 [0.65–3.13] | 3.35 [0.97–11.58] |
| Liver Cirrhosis | — | — | — |
| Chronic kidney disease | 7.33 [3.17–16.96] | 7.11 [3.08–16.43] | 23.12 [4.90–109] |
| Renal failure | — | — | — |
*
The covariates which caused at least a 10% shift in the risk estimate for the univariate analysis were adjusted in the final model. The COX model for each analysis was constructed separately.
†
We categorized the continuous propensity score into 20 strata of 5% each for the distribution of scores. The covariates which caused at least a 10% shift in the risk estimate after given by stratum of propensity score were adjusted in the final model.
‡
Variables in propensity score matched cohort were adjusted for stratum of propensity score only, which were estimated using the same variables.