Table 4:
GEE model output on all-cause 30-day acute care utilization post-index by Beers criteria compliance
| Characteristics* | Adjusted RR** | 95%CI | P-values | |
|---|---|---|---|---|
|
| ||||
| Any PIM combination (ref: no PIM) | 1.23 | 1.02 | 1.48 | 0.032 |
| Female sex | 1.01 | 0.89 | 1.15 | 0.881 |
| Age group | ||||
| 65–74 (ref) | ||||
| 75–84 | 1.19 | 1.02 | 1.40 | 0.031 |
| 85+ | 1.57 | 1.26 | 1.95 | <.001 |
| Charlson Comorbidity Index | ||||
| 3 (ref) | ||||
| 4 | 1.17 | 0.96 | 1.42 | 0.113 |
| 5+ | 1.76 | 1.47 | 2.10 | <.001 |
| History of mental health conditions | ||||
| Mood disorders | 1.13 | 0.88 | 1.46 | 0.335 |
| Psychoses | 1.65 | 1.26 | 2.15 | <.001 |
| Behavior disorders | 0.93 | 0.64 | 1.35 | 0.698 |
| History of ER visits** | 1.64 | 1.22 | 2.20 | 0.001 |
| History of admission** | 1.51 | 1.00 | 2.28 | 0.052 |
| Hydrocodone (ref) | ||||
| Oxycodone | 0.94 | 0.70 | 1.27 | 0.687 |
| Codeine | 1.05 | 0.89 | 1.23 | 0.554 |
| Others | 1.28 | 0.99 | 1.66 | 0.059 |
| Every 10 mg OME increase | 1.01 | 1.00 | 1.02 | 0.027 |
Abbreviations: GEE: generalized estimating equations; RR, relative risk; CI, confidence interval; PIM, potentially inappropriate medication; ER, emergency room; OME, oral morphine equivalent.
Due to low event per category in dental procedure variable, we did not include the dental procedures into the model to avoid sparse data bias and its resulting considerable upward bias.
Adjusted RR using Proc GenMod – Modified Poisson regression model Poisson regression without robust error variances may result in a conservative CI (i.e., wider CI). A “modified Poisson” method has been proposed to estimate the RR using a robust error variance (Zou 2004). This method leads to the robust error variance estimation and produces 95% CIs with the correct coverage.
Using AR(1) correlation structure