Scenario analyses with incremental costs, QALYs gained and ICERs (expected value analysis for population-level results for the lifetime of the modelled cohort of community-dwelling older people)
| Intervention/output | Output | No HSAM—baseline) | Impact of HSAM compared with baseline |
|---|---|---|---|
| Baseline model (3% discount rate) | |||
| Net cost (NZ$; 1000s) | Mean | $41 700 000 | $111 000 |
| 95% UI | ($41 400 000 to $42 400 000) | (Cost saving to $197 000) | |
| QALYs gained | Mean | 4 100 000 | 34 000 |
| 95% UI | (3 970 000 to 4 230 000) | (5490 to 65 300) | |
| ICER | Mean | $9000 | |
| Median | $4000 | ||
| 95% UI | (Cost saving to $20 000) | ||
| HSAM targeted to ‘at risk’ older people aged 65 years and above with one or more previous injurious falls | |||
| Net cost (NZ$; 1000s) | Mean | $41 700 000 | $6170 |
| 95% UI | ($41 400 000 to $42 400 000) | (Cost saving to $29 900) | |
| QALYs gained | Mean | 4 100 000 | 20 100 |
| 95% UI | (3 970 000 to 4 230 000) | (3010 to 40 300) | |
| ICER | Mean | $2000 | |
| Median | $700 | ||
| 95% UI | (Cost saving to $4000) | ||
| HSAM targeted to older people aged 75 years and above | |||
| Net cost (NZ$; 1000s) | Mean | $16 300 000 | $59 100 |
| 95% UI | ($16 200 000 to $16 400 000) | ($30 000 to $87 100) | |
| QALYs gained | Mean | 1 180 000 | 8750 |
| 95% UI | (1 150 000 to 1 210 000) | (1400 to 16 700) | |
| ICER | Mean | $17 000 | |
| Median | $7000 | ||
| 95% UI | ($2000 to $34 000) | ||
| Discount rate 0% (otherwise same as baseline model) | |||
| Net cost (NZ$; 1000s) | Mean | $55 900 000 | $198 000 |
| 95% UI | ($55 700 000 to $56 400 000) | ($95 200 to $294 000) | |
| QALYs gained | Mean | 5 160 000 | 48 200 |
| 95% UI | (4 980 000 to 5 350 000) | (7930 to 92 400) | |
| ICER | Mean | $8000 | |
| Median | $4000 | ||
| 95% UI | ($1000 to $16 000) | ||
| Discount rate doubled to 6% (otherwise same as baseline model) | |||
| Net cost (NZ$; 1000s) | Mean | $32 800 000 | $71 800 |
| 95% UI | ($32 300 000 to $33 600 000) | (Cost saving to $167 000) | |
| QALYs gained | Mean | 3 390 000 | 25 300 |
| 95% UI | (3 290 000 to 3 480 000) | (4030 to 49 100) | |
| ICER | Mean | $11 000 | |
| Median | $3000 | ||
| 95% UI | (Cost saving to $25 000) | ||
| HSAM targeted to at-risk older people aged 65 years and above with one or more previous injurious falls with declining effectiveness over 10 years | |||
| Net cost (NZ$; 1000s) | Mean | $41 700 000 | $112 000 |
| 95% UI | ($41 400 000 to $42 400 000) | ($20 700 to $184 000) | |
| QALYs gained | Mean | 4 100 000 | 16 500 |
| 95% UI | (3 970 000 to 4 230 000) | (2660 to 33 000) | |
| ICER | Mean | $20 000 | |
| Median | $7000 | ||
| 95% UI | ($400 to $41 000) | ||
| HSAM targeted to at-risk older people aged 65 years and above with home modification costs reduced to one-third (government achieves economies of scale with purchasing interventions) | |||
| Net cost (NZ$; 1000s) | Mean | $41 700 000 | $64 800 |
| 95% UI | ($41 400 000 to $42 400 000) | (Cost saving to $137 000) | |
| QALYs gained | Mean | 4 100 000 | 34 000 |
| 95% UI | (3 970 000 to 4 200 000) | (5490 to 65 300) | |
| ICER | Mean | $6000 | |
| Median | $2000 | ||
| 95% UI | (Cost saving to $13 000) | ||
| Hypothetical intervention for context: HSAM targeted to at-risk older people aged 65 years and above with one or more previous injurious falls with 100% effectiveness | |||
| Net cost (NZ$; 1000s) | Mean | $41 700 00 | Cost saving |
| 95% UI | ($41 400 000 to $42 400 000) | (Cost saving to $266 000) | |
| QALYs gained | Mean | 4 100 000 | 203 000 |
| 95% UI | (3 970 000 to 4 230 000) | (96 400 to 302 000) | |
| ICER | Mean | $100 | |
| Median | $200 | ||
| 95% UI | (Cost saving to $3000) | ||
| HSAM with risk-specific effectiveness, RR high-risk group=0.62 (95% CI=0.50 to 0.77), RR low-risk group=0.94 (0.84, 1.05) as per a Cochrane systematic review7 | |||
| Net cost (NZ$; 1000s) | Mean | $41 700 000 | $108 800 |
| 95% UI | ($41 400 000 to $42 400 000) | (Cost saving to $204 500) | |
| QALYs gained | Mean | 4 100 000 | 42 800 |
| 95% UI | (3 970 000 to 4 230 000) | (1800–86 200) | |
| ICER | Mean | $5000 | |
| Median | $3000 | ||
| 95% UI | (Cost saving—$22 000) | ||
ICERs rounded to the nearest $1000 or, if lower than $1000, to the nearest $100. Other values are rounded to three meaningful digits.
HSAM, home safety assessment and modification; ICER, incremental cost-effectiveness ratio; NZ, New Zealand; QALYs, quality-adjusted life-years; UI, uncertainty interval.