Adjusted segmented regression of hemoglobin A1c before the Ontario Health Insurance Plan (OHIP)+ program began (Jan. 1, 2016, to Dec. 31, 2017) and during OHIP+ (Apr. 1, 2018, to Mar. 31, 2019) including interaction terms to evaluate if the change in temporal trend of hemoglobin A1c differed according to socioeconomic status (n = 6347 youth; n = 32 802 measurements of hemoglobin A1c)
| Variable | β estimate (95% CI) |
|---|---|
| Mean HbA1c on Jan. 1, 2016, by material deprivation quintile | |
| Q1 (least deprived) | 8.5693 (8.4601 to 8.6785) |
| Q2 | 8.6765 (8.5486 to 8.8043) |
| Q3 | 8.6002 (8.4708 to 8.7296) |
| Q4 | 8.8165 (8.6656 to 8.9674) |
| Q5 (most deprived) | 8.8779 (8.7123 to 9.0435) |
| Before OHIP+ slope (change in HbA1c per day), by material deprivation quintile | |
| Q1 (least deprived) | −0.0128 (−0.0254 to 0.0002) |
| Q2 | 0.0011 (−0.0125 to 0.0147) |
| Q3 | 0.0101 (−0.0062 to 0.0264) |
| Q4 | 0.0083 (−0.0099 to 0.0264) |
| Q5 (most deprived) | 0.0189 (0.0009 to 0.0387) |
| Change in slope from before OHIP+ to after Apr. 1, 2018, by material deprivation quintile | |
| Q1 (least deprived) | 0.0001 (−0.0003 to 0.0004) |
| Q2 | 0.0001 (−0.0003 to 0.0005) |
| Q3 | −0.0002 (−0.0007 to 0.0003) |
| Q4 | −0.0005 (−0.0011 to 0.0001) |
| Q5 (most deprived) | −0.0007 (−0.0013 to 0.0001) |
| Difference in mean HbA1c on Jan. 1, 2016, compared with Q1 (least deprived) | |
| Q2 | 0.1072 (−0.0491 to 0.2635) |
| Q3 | 0.0309 (−0.1284 to 0.1903) |
| Q4 | 0.2472 (0.0724 to 0.4221) |
| Q5 (most deprived) | 0.3086 (0.1207 to 0.4965) |
| Difference in slope before OHIP+, by material deprivation quintile compared with Q1 (least deprived) | |
| Q2 | 0.0002 (−0.0001 to 0.0004) |
| Q3 | 0.0003 (0.000 to 0.0005) |
| Q4 | 0.0002 (0.000 to 0.0005) |
| Q5 (most deprived) | 0.0004 (0.0001 to 0.0006) |
| Change in slope from before OHIP+ to after Apr. 1, 2018, by material deprivation quintile compared with Q1 (least deprived) | |
| Q2 | 0.0000 (−0.0005 to 0.0006 |
| Q3 | −0.0003 (−0.0009 to 0.0004) |
| Q4 | −0.0006 (−0.0012 to 0.0001) |
| Q5 (most deprived) | −0.0008 (−0.0015 to 0.0001) |
| Age (centred on 14 yr) | 0.0041 (−0.0077 to 0.0158) |
| Male | −0.0571 (−0.1435 to 0.0292) |
| Duration of diabetes (centred on 7 yr) | 0.0417 (0.0293 to 0.0541) |
Note: CI = confidence interval, HbA1c = hemoglobin A1c.