Table 1.
Model parameters
| Input variables | Base case* | Range for sensitivity analysis | Source |
| Resource costs† | |||
| Cost of evaluating a patient for HAPI | $2.76 | 2.35 to 3.17 | 25 |
| Cost of a stage 3, 4 or unstageable HAPI | $6209.53 | 5278.10 to 7140.96 | 34 35 |
| Cost of an inpatient hospital stay | $2122.53 | 1804.15 to 2440.91 | 15 |
| Cost of prevention (total) | $99.44 | 84.52 to 114.36 | |
| Skin checks | $8.10 | – | 25 |
| Repositioning | $15.61 | – | 25 |
| Group II hospital bed | $24.41 | – | 26 |
| Chair cushion | $0.33 | – | 15 |
| Managing moisture/incontinence | $29.81 | – | 15 |
| Nutrition | $1.28 | – | 15 |
| Nursing education | $0.01 | – | Assumed |
| Unforeseen costs (25%) | $19.89 | – | Assumed |
| Cost of lost productivity per day | $132.38 | 112.52 to 152.24 | 25 |
| QALYs | |||
| Utility of an inpatient | 0.827 | 0.703 to 0.951 | 15 |
| Utility of a HAPI | 0.597 | 0.507 to 0.687 | 15 |
| Disutility of a patient in acute and chronic care | −0.015 | −0.013 to −0.017 | 15 |
| Disutility of surgery | −0.155 | −0.132 to −0.178 | 15 |
| Final utility at discharge | 13.23 | 11.24 to 15.21 | 15 |
| Probabilities | |||
| Initial probability very high risk (Braden 6–9) | 0.0733 | 0.0623 to 0.0843 | Original data |
| Initial probability high risk (Braden 10–12) | 0.0186 | 0.0158 to 0.0214 | Original data |
| Initial probability moderate risk (Braden 13–14) | 0.1216 | 0.1034 to 0.1398 | Original data |
| Initial probability at risk (Braden 15–18) | 0.2988 | 0.2540 to 0.3436 | Original data |
| Initial probability minimal risk (Braden 19–23) | 0.4877 | 0.4145 to 0.5609 | Original data |
| Probability of death after a stage III/IV HAPI | 0.0723 | 0.0615 to 0.0831 | 15 |
| Probability of death from surgery | 0.000012 | 0.000010 to 0.000014 | 15 |
| Probability of acute and chronic care | 0.16 | 0.14 to 0.18 | 15 |
| Probability of surgery | 0.77 | 0.65 to 0.88 | 15 |
| Odds ratios | |||
| OR of HAPI incidence after prevention | 0.335 | 0.285 to 0.385 | 24 |
*Base case refers to the expected value (eg, observable mean) of the select parameter for the deterministic model. Probabilistic models assumed prior distributions from the ranges shown for sensitivity analysis.
†Costs are expressed per day, thus each cost listed in the table accumulates repeatedly with each additional model cycle. These cost data came from secondary data sources and are adjusted for inflation to reflect 2017 current values.
HAPI, hospital-acquired pressure injury; QALY, quality-adjusted life-year.