Table 2. Main results and scenario analyses for the home safety assessment and modification intervention (HSAM) in a single health district (Counties Manukau District Health Board).
| Intervention/Output | Output | Baseline (no HSAM)* | Impact of HSAM compared to baseline* |
|---|---|---|---|
| Base-case intervention (3% discount rate) | |||
| Net cost (NZ$; 1000s) | Mean | $3,040,000 | $8440 |
| 95%UI | ($3,010,000 –$3,110,000) | ($663 –$14,300) | |
| QALYs gained | Mean | 331,000 | 2800 |
| 95%UI | (321,000–342,000) | (547–5280) | |
| ICER | Mean | Not applicable (NA) | $5480 |
| Median | NA | $3310 | |
| 95%UI | NA | (cost saving–$15,300) | |
| HSAM targeted to “at risk” people aged 65+ years with one or more previous injurious falls | |||
| Net cost ($; 1000s) | Mean | $3,040,000 | $91 |
| 95%UI | ($3,010,000 –$3,110,000) | (cost saving–$2140) | |
| QALYs gained | Mean | 331,000 | 1420 |
| 95%UI | (321,000–342,000) | (258–2760) | |
| ICER | Mean | NA | $701 |
| Median | NA | $331 | |
| 95%UI | NA | (cost saving–$2740) | |
| HSAM targeted to people aged 65+ years but with no history of previous injurious falls | |||
| Net cost ($; 1000s) | Mean | $3,040,000 | $8340 |
| 95%UI | ($3,010,000 –$3,110,000) | ($3770 –$12,800) | |
| QALYs gained | Mean | 331,000 | 1520 |
| 95%UI | (321,000–342,000) | (292–2940) | |
| ICER | Mean | NA | $9600 |
| Median | NA | $5790 | |
| 95%UI | NA | ($1410 –$26,300) | |
| HSAM targeted to people aged 75+ years | |||
| Net cost ($; 1000s) | Mean | $963,000 | $2430 |
| 95%UI | ($951,000 –$987,000) | (cost saving–$4830) | |
| QALYs gained | Mean | 85,700 | 592 |
| 95%UI | (83,800–87,800) | (116–1120) | |
| ICER | Mean | NA | $8490 |
| Median | NA | $4620 | |
| 95%UI | NA | (cost saving–$24,500) | |
| HSAM targeted to “at risk” people aged 75+ years with one or more previous injurious falls | |||
| Net cost ($; 1000s) | Mean | $963,000 | $-163 |
| 95%UI | ($951,000 –$987,000) | (cost saving–$484) | |
| QALYs gained | Mean | 85,700 | 281 |
| 95%UI | (83,800–87,800) | (52–546) | |
| ICER | Mean | NA | $832 |
| Median | NA | $-87 | |
| 95%UI | NA | (cost saving–$4604) | |
| HSAM targeted to people aged 75+ years but with no history of previous injurious falls | |||
| Net cost ($; 1000s) | Mean | $963,000 | $2540 |
| 95%UI | ($951,000 –$987,000) | ($282 –$4420) | |
| QALYs gained | Mean | 85,700 | 338 |
| 95%UI | (83,800–87,800) | (64–648) | |
| ICER | Mean | NA | $14,260 |
| Median | NA | $8020 | |
| 95%UI | NA | ($206 –$40,200) | |
| Discount rate 0% (otherwise same as base-case model) | |||
| Net cost ($; 1000s) | Mean | $4,070,000 | $14,000 |
| 95%UI | ($4,050,000 –$4,130,000) | ($7160 –$21,200) | |
| QALYs gained | Mean | 427,000 | 4160 |
| 95%UI | (412,000–444,000) | (813–7860) | |
| ICER | Mean | NA | $5030 |
| Median | NA | $3560 | |
| 95%UI | NA | ($1170 –$11,600) | |
| Discount rate doubled to 6% (otherwise same as base-case model) | |||
| Net cost ($; 1000s) | Mean | $2,390,000 | $6110 |
| 95%UI | ($2,360,000 –$2,460,000) | (cost saving–$12,300) | |
| QALYs gained | Mean | 270,000 | 2010 |
| 95%UI | (262,000–277,000) | (392–3830) | |
| ICER | Mean | NA | $6440 |
| Median | NA | $3420 | |
| 95%UI | NA | (cost saving–$20,100) | |
| HSAM targeted to at risk older people aged 65+ years with one or more previous injurious falls with declining HSAM intervention effectiveness over 10 years | |||
| Net cost ($; 1000s) | Mean | $3,040,000 | $9430 |
| 95%UI | ($3,014,000 –$3,110,000) | ($5600 –$13,000) | |
| QALYs gained | Mean | 331,000 | 1230 |
| 95%UI | (321,000–342,000) | (222–2470) | |
| ICER | Mean | NA | $12,900 |
| Median | NA | $8100 | |
| 95%UI | NA | ($2600 –$38,900) | |
| HSAM targeted to at risk older people aged 65+ years with home modification costs hypothetically reduced by one third (funder achieves economies of scale with purchasing interventions) | |||
| Net cost ($; 1000s) | Mean | $3,040,000 | $5860 |
| 95%UI | ($3,010,000 –$3,110,000) | (cost saving–$10,900) | |
| QALYs gained | Mean | 331,000 | 2800 |
| 95%UI | (321,000–342,000) | (547–5280) | |
| ICER | Mean | NA | $3920 |
| Median | NA | $2390 | |
| 95%UI | NA | (cost saving–$11,600) | |
| Base-case model but with just a 10 year time horizon for benefits and costs | |||
| Net cost ($; 1000s) | Mean | $2,050,000 | $3290 |
| 95%UI | ($2,014,000 –$2,120,000) | (cost saving–$10,600) | |
| QALYs gained | Mean | 247,000 | 1380 |
| 95%UI | (241,000–252,000) | (264–2760) | |
| ICER | Mean | NA | $7220 |
| Median | NA | $2940 | |
| 95%UI | NA | (cost saving–$29,700) | |
| Base-case model but with just a 20 year time horizon for benefits and costs | |||
| Net cost ($; 1000s) | Mean | $2,830,000 | $4950 |
| 95%UI | ($2,790,000 –$2,910,000) | (cost saving–$11,800) | |
| QALYs gained | Mean | 315,0000 | 2360 |
| 95%UI | (306,000–324,000) | (466–4540) | |
| ICER | Mean | NA | $4980 |
| Median | NA | $2470 | |
| 95%UI | NA | (cost saving–$17,200) | |
Note
*Results are rounded to three meaningful digits.
ICER: incremental cost-effectiveness ratio; QALY: quality-adjusted life-year; 95%UI: 95% uncertainty interval.