Table 3.
Results (HR (95%CI)) from Cox proportional hazards models estimating the association metformin (MET) vs. sulfonylurea (SU) and incident dementia in FY2002 to FY2015, overall and stratified by age among VHA patients ≥50 years old (n=75,187) and KPW patients ≥50 years old (n=10,866)
| Model 1 – Crudea MET vs. SU: | Model 2–Weightedb MET vs. SU: | Model 3 −Weighted + AMGBc MET vs. SU: | Model 4−Weighted + hypoglycemic episode MET vs. SU | |||||
|---|---|---|---|---|---|---|---|---|
| Age group | VA patients | KPW patients | VA patients | KPW patients | VA patients | KPW patients | VA patients | KPW patients |
| All ages ≥ 50 years | 0.66 (0.62–0.70) |
0.37 (0.32–0.44) |
0.93 (0.87–0.99) |
0.89 (0.74–1.07) |
0.89 (0.83–0.95) |
0.88 (0.73–1.07) |
0.95 (0.78–0.99) |
0.89 (0.73–1.07) |
| Age Strata | ||||||||
| Age 50–64 years | 0.85 (0.75–0.95) |
1.04 (0.67–1.61) |
0.86 (0.76–0.98) |
1.33 (0.78–2.25) |
0.84 (0.73–0.96) |
1.35 (0.79–2.28) |
0.89 (0.78–1.02) |
1.36 (0.80–2.31) |
| Age 65–74 years | 0.87 (0.80–0.95) |
0.76 (0.58–0.98) |
0.87 (0.80–0.96) |
0.79 (0.58–1.07) |
0.87 (0.79–0.96) |
0.78 (0.58–1.06) |
0.89 (0.81–0.98) |
0.79 (0.58–1.08) |
| Age ≥75 years | 1.05 (0.95–1.16) |
0.78 (0.62–0.99) |
1.03 (0.9–1.14) |
0.79 (0.60–1.03) |
1.02 (0.91–1.15) |
0.82 (0.62–1.07) |
1.05 (0.94–1.16) |
0.81 (0.61–1.06) |
Note: VHA=Veterans Health Administration; KPW=Kaiser Permanente Washington State; FY=Fiscal Year; MET=Metformin; SU=Sulfonylurea; AMGB=average monthly glycemic burden; HR=hazard ratio; CI=confidence interval
Unweighted data
Inverse probability of treatment weighted data with robust, sandwich-type variance estimators
Additional adjustment for glycemic burden from MET/SU initiation to end of follow-up among a subset of 71,266 VA patients and 10,743 with at least 2 HbA1c values after MET/SU initiation