Table 3.
Variances and variance ratios before and after matching and weighting
| Baseline period characteristic | Before matching/weighting | After matching/weighting | ||||
| Treated (n=11 646) |
Untreated (73 973) |
Ratio | Treated (n=11 646) |
Untreated (n=26 601) |
Ratio | |
| Medicare | 0.22 | 0.25 | 0.89 | 0.22 | 0.22 | 1.00 |
| SSI disabled | 0.25 | 0.17 | 1.44 | 0.25 | 0.25 | 1.00 |
| SSI aged | 0.16 | 0.25 | 0.65 | 0.16 | 0.16 | 1.00 |
| Any hospitalization | 0.24 | 0.20 | 1.23 | 0.24 | 0.24 | 1.00 |
| Any ED visit | 0.23 | 0.17 | 1.38 | 0.23 | 0.23 | 1.00 |
| Months enrolled in Medicaid | 2.40 | 2.54 | 0.95 | 2.40 | 2.40 | 1.00 |
| Age | 158.74 | 255.11 | 0.62 | 158.74 | 158.73 | 1.00 |
| Inpatient diabetes dx | 0.22 | 0.16 | 1.34 | 0.22 | 0.22 | 1.00 |
| Outpatient diabetes dx | 0.21 | 0.24 | 0.87 | 0.21 | 0.21 | 1.00 |
| SMI dx | 0.25 | 0.21 | 1.19 | 0.25 | 0.25 | 1.00 |
| SUD dx | 0.20 | 0.07 | 2.84 | 0.20 | 0.20 | 1.00 |
| Cancer dx | 0.13 | 0.13 | 0.99 | 0.13 | 0.13 | 1.00 |
| HIV dx | 0.22 | 0.08 | 2.86 | 0.22 | 0.22 | 1.00 |
| Number of chronic dxs | 88.36 | 93.57 | 0.94 | 88.36 | 88.36 | 1.00 |
| Index month (relative to January 2010) | 179 320.28 | 264 829.06 | 0.68 | 179 320.28 | 179 311.62 | 1.00 |
| Non-Hispanic white | 0.09 | 0.16 | 0.61 | 0.09 | 0.09 | 1.00 |
| Non-Hispanic black | 0.21 | 0.17 | 1.25 | 0.21 | 0.21 | 1.00 |
| Metformin prescriptions in months 1–6 | 5.19 | 3.76 | 1.38 | 5.19 | 5.19 | 1.00 |
| Metformin prescriptions in months 7–12 | 5.10 | 3.61 | 1.41 | 5.10 | 5.10 | 1.00 |
| Insulin prescriptions in months 1–6 | 0.17 | 0.09 | 1.87 | 0.17 | 0.17 | 1.00 |
| Insulin prescriptions in months 7–12 | 0.18 | 0.10 | 1.88 | 0.18 | 0.18 | 1.00 |
| UPC Index | 0.11 | 0.16 | 0.70 | 0.11 | 0.11 | 1.00 |
| Undefined UPC Index | 0.12 | 0.21 | 0.58 | 0.12 | 0.12 | 1.00 |
| COC Index | 0.13 | 0.15 | 0.86 | 0.13 | 0.13 | 1.00 |
| Undefined COC Index | 0.17 | 0.24 | 0.72 | 0.17 | 0.17 | 1.00 |
| Month 1 cost | 1.01e+08 | 8.43e+07 | 1.19 | 1.01e+08 | 1.01e+08 | 1.00 |
| Month 2 cost | 7.83e+07 | 9.00e+07 | 0.87 | 7.83e+07 | 7.83e+07 | 1.00 |
| Month 3 cost | 8.05e+07 | 9.40e+07 | 0.86 | 8.05e+07 | 8.05e+07 | 1.00 |
| Month 4 cost | 8.22e+07 | 1.13e+08 | 0.73 | 8.22e+07 | 8.22e+07 | 1.00 |
| Month 5 cost | 7.94e+07 | 8.82e+07 | 0.90 | 7.94e+07 | 7.94e+07 | 1.00 |
| Month 6 cost | 9.21e+07 | 1.17e+08 | 0.79 | 9.21e+07 | 9.21e+07 | 1.00 |
| Month 7 cost | 5.63e+07 | 9.35e+07 | 0.60 | 5.63e+07 | 5.62e+07 | 1.00 |
| Month 8 cost | 6.95e+07 | 1.00e+08 | 0.69 | 6.95e+07 | 6.95e+07 | 1.00 |
| Month 9 cost | 7.66e+07 | 8.63e+07 | 0.89 | 7.66e+07 | 7.66e+07 | 1.00 |
| Month 10 cost | 6.80e+07 | 6.71e+07 | 1.01 | 6.80e+07 | 6.80e+07 | 1.00 |
| Month 11 cost | 5.88e+07 | 8.40e+07 | 0.70 | 5.88e+07 | 5.88e+07 | 1.00 |
| Month 12 cost | 1.29e+08 | 8.63e+07 | 1.50 | 1.29e+08 | 1.29e+08 | 1.00 |
| Hospitalizations | 4.49 | 1.25 | 3.59 | 4.49 | 4.49 | 1.00 |
| ED visits | 16.37 | 4.55 | 3.60 | 16.37 | 16.37 | 1.00 |
| PCP visits | 190.58 | 111.02 | 1.72 | 190.58 | 190.57 | 1.00 |
| Specialty visits | 215.06 | 219.31 | 0.98 | 215.06 | 215.05 | 1.00 |
The ‘baseline period’ comprised the 12 calendar months before the calendar month that contained the index date.
Undefined UPC indices (<2 visits) and undefined COC indices (<1 visit) were assigned values of zero for purposes of matching/weighting.
‘Visits were defined as the number of unique combinations of provider ID, Medicaid ID, and dates within the baseline period.
COC, Continuity of Care; dx, International Classification of Diseases (ICD) 9/10 diagnosis; ED, emergency department; ID, identification; PCP, primary care provider; SMI, serious mental illness; SSI, Supplemental Security Income; SUD, substance use disorder; UPC, Usual Provider of Care.