Table 2:
Comparison of prediction performance using any of the Medicaid opioid quality measures versus GBM in the 2013–16 Pennsylvania internal validation sample (n=135 106) over a 12-month period*
| Any Medicaid core set opioid measure† |
High risk in GBM using different thresholds‡ |
||||
|---|---|---|---|---|---|
| Low risk (n=122 538, 90·7%) | High risk (n=12 568, 9·3%) | Top first percentile (n=4570, 3·4%) | Top fifth percentile (n=11 053, 8·2%) | Top tenth percentile (n=23 158, 17·1%) | |
|
| |||||
| Number of actual overdoses (% of each subgroup) | 639 (0·5%) | 204 (1·6%) | 299 (6·5%) | 557 (5·0%) | 713 (3·1%) |
| Number of actual non-overdoses (% of each subgroup) | 121 899 (99·5%) | 12 364 (98·4%) | 4271 (93·5%) | 10 496 (95·0%) | 22 445 (96·9%) |
| Number needed to evaluate | NA | 62 | 15 | 19 | 32 |
| % of all overdoses over 12 months (n=843) captured | 75·8% | 24·2% | 35·5% | 66·1% | 84·6% |
MME=morphine milligram equivalent. GBM=gradient boosting machine.
To compare with Medicaid opioid measures, beneficiaries were required to have at least a 12-month period of follow-up and the resulting sample size was smaller than the sample size in the main analysis. If classifying beneficiaries with any of the Medicaid high-risk opioid use measures as opioid overdose, those remaining would be considered as non-overdose.
The Medicaid opioid quality measures included in the Core Set of Adult Health Care Quality Measures for Medicaid or Medicaid Section 1115 Substance Use Disorder Demonstrations to identify high-risk individuals or use behaviour in Medicaid. These simple measures include three metrics: (1) high-dose use, defined as >120 MME for ≥90 continuous days, (2) ≥4 opioid prescribers and ≥4 pharmacies, and (3) concurrent opioid and benzodiazepine use ≥30 days.
For GBM, we presented high-risk groups using different cutoff thresholds of prediction probability: individuals with (1) predicted score in the top first percentile (≥98·3); (2) predicted probability in the top fifth percentile (≥96·6); and (3) predicted probability in the top tenth percentile (≥64·9). If classifying beneficiaries in the high-risk group of opioid overdoses, those remaining would be considered as non-overdose.