Table 4.

Intent to Treat and Connection to Health Per Protocol Comparisons of Impact on Hemoglobin A1c over Time

Outcome Is HbA1c Over TimeIntent to Treat, N = 1022Connection to Health Per Protocol, N = 458
VariableAdjusted Models, Coef (SE)P-ValueAdjusted Models, Coef (SE)P-Value
Intercept7.5385 (0.1941)<.00016.6848 (0.2368)<.0001
Age group (years)
    17 to 49RefRef
    50 to 640.8017 (0.1368)<.00010.8571 (0.1956)<.0001
    65 or greater−1.2746 (0.1449)<.0001−1.057 (0.2199)<.0001
Female gender0.0881 (0.1034).39420.2259 (0.1572).1509
BMI (at baseline, centered)−0.0232 (0.0070).0010−0.0436 (0.0105)<.0001
Pulmonary−0.4775 (0.2289).0371
Diabetic retinopathy0.3368 (0.1595).0348
Renal0.4531 (0.2587).0801
Oral diabetic medications0.7150 (0.1287)<.00010.6452 (0.1817).0004
Insulin1.7418 (0.1117)<.00011.7147 (0.1663)<.0001
Intervention vs SMS-ED (at baseline)
    CTH vs SMS-ED−0.0987 (0.1551).5245−0.049 (0.3530).8891
    CTH + PF vs SMS-ED0.0160 (0.1524).91640.6519 (0.2300).0047
HbA1c change per 12 months (slope)Compared to SMS−EDCompared to SMS−ED
SMS-ED0.1638 (0.0853)0.1546 (0.0920)
CTH0.3022 (0.0756).22430.0671 (0.2255).7193
CTH + PF0.1441 (0.0721).8601−0.1640 (0.1269).0422
  • BMI, body mass index; CTH, Connection to Health; CTH + PF, Connection to Health with practice facilitation; HbA1c, hemoglobin A1c; SMS-ED, self-management support education; SE, standard error.

  • Overall P-value for group x time: 0.2724. The overall group x time effect is used to determine whether there are differences in slopes between the three study arms. The coefficients in the table show the actual slopes (SE) for each study arm, along with the p-value for the differences for CTH vs SMS-ED, and CTH + PF vs SMS-ED.