Table 4

Intervention Effects on HbA1c, Blood Pressure, Health Care Use, and Diabetes Management Behaviors (N = 304)

BaselineTime (Baseline to 12 Months)Group*Time
Beta EstimateSEP ValueBeta EstimateSEP ValueBeta EstimateSEP Value
Health Status (medical record)
HbA1ca0.01630.0257.530.000020.00004.15−0.000120.00006.05
Systolic blood pressurea0.03020.0195.120.000050.00003.30−0.000040.00005.38
Diastolic blood pressurea0.01390.0161.39−0.000030.00003.180.000000.00004.92
Health care use (interview)
Planned diabetes care visitsb−0.01700.0959.86−0.000500.00023.020.000200.00034.56
Diabetes management behaviors (interview)
Days in past week …
 5+ fruits & vegetables consumedb−0.14720.0929.11−0.000200.00018.870.000440.00026.09
 High fat foods consumedb0.15140.1115.180.000040.00018.52−0.000250.00027.35
 30 minutes of physical activityb−0.11990.1289.350.000110.00025.410.000100.00038.80
 Blood sugar checkedb−0.04320.0871.620.000220.00011.02−0.000060.00017.74
 Feet checkedb0.01690.0683.810.000530.00012<.001−0.000370.00017.03
 Medication adherencec−0.16110.2830.570.001630.00051<.001−0.000340.00074.64
  • The Beta estimate can be interpreted as follows: Group: the adjusted mean difference in the outcome between intervention and usual care participants at baseline. Time: the adjusted rate of change per day in the outcome among all participants. Group*Time: the adjusted rate of change (per day) in the outcome among intervention vs usual care participants. For example, log-transformed HbA1c was 0.0163 points higher among intervention participants than among usual care participants at baseline (P = .53). Among all participants, log-transformed HbA1c increased from baseline to 12 months by 0.00002 points per day (P = .15). From baseline to 12 months, log-transformed HbA1c decreased by −0.00012 more points per day among intervention participants than among usual care participants (P = .05).

  • a Fitted 3 level linear mixed models for log-transformed outcomes, adjusting for clustering at individual and clinic levels, and the following covariates: poverty status, having a personal doctor, medication adherence, and intervention dose.

  • b Fitted 3 level Poisson regression for counts, adjusting for clustering at individual and clinic levels and for the following covariates: poverty status, having a personal doctor, medication adherence, and intervention dose.

  • c Fitted 3 level logistic regression model for a binary outcome, adjusting for clustering at individual and clinic levels and for the following covariates: poverty status, having a personal doctor, and intervention dose.