Table 2

Predictors of initial shared medical record use during study period using Cox proportional hazards model with baseline variables

Baseline predictorUnadjusted HR of SMR use*Adjusted HR of SMR use
Age category (years)
    65–69Ref.Ref.
    70–740.77 (0.69–0.86)0.76 (0.68–0.85)
    ≥750.55 (0.50–0.62)0.57 (0.51–0.63)
Female sex0.71 (0.65–0.78)0.72 (0.66–0.79)
Low neighborhood SES0.77 (0.69–0.85)0.80 (0.72–0.89)
>30 min distance from clinic1.21 (1.04–1.42)1.13 (0.96–1.33)
Overall morbidity
    Moderate or lowerRef.Ref.
    High1.06 (0.96–1.18)1.12 (1.01–1.25)
    Very high1.04 (0.93–1.17)1.15 (1.02–1.29)
PCP use of secure messaging (10% difference)1.10 (1.04–1.15)1.12 (1.06–1.19)
Insulin use1.04 (0.94–1.15)1.00 (0.91–1.11)
  • Data are hazard ratios (95% CI). Hazard ratio compares rate of initial use (number of initial users per day) relative to reference group.

  • *One model for each variable.

  • †Adjusted model includes all variables in table (n = 5,500). HR, hazard ratio.