Table 3.
Primary analysis: costs attributable to PIP
| Health service/cost category | No. of participants with PIP | IRR with PIP vs. no PIP (95% CI) | PIP prevalence (%) | Population attributable fraction [% (95% CI)] | Total costs (2017 CAN$) | Costs attributable to PIP (2017 CAN$)b | Cost per individual [2017 CAN$ (95% CI)] |
|---|---|---|---|---|---|---|---|
| Hospitalization | 1,581,897 | 2.77 (2.72–2.82) | 70.1 | 55.3 (54.7–56.1) | 2,000,286,464 | 1,107,608,294 | 699.97 (691.01–708.66) |
| ED visits | 1,581,897 | 1.87 (1.82–1.92) | 70.1 | 37.9 (36.5–39.2) | 172,289,790 | 65,268,856 | 41.24 (39.74–42.69) |
| Medicationa | 907,993 | 1.13 (1.13–1.14) | 40.2 | 5.0 (5.0–5.3) | 975,197,362 | 48,432,720 | 53.32 (53.32–57.21) |
| Total | 3,147,773,616 | 1,221,309,870 | 772.83 (761.36–784.19) | ||||
CI confidence interval, CAN$ Canadian dollars, PIP potentially inappropriate prescription, IRR incidence rate ratio, ED emergency department, STOPP Screening Tool of Older People’s Prescriptions, START Screening Tool to Alert Doctors to Right Treatment
aIncludes only those with a STOPP criterion as their first PIP. All participants with a START criterion as their first PIP, multiple first PIP, or an overlapping second PIP within their 90-day outcome observation window were removed and the prevalence was recalculated
bCosts attributable to PIP were determined by multiplying the unrounded population attributable fraction by the total costs