Table 1

Model parameters

Input variablesBase case*Range for sensitivity analysisSource
Resource costs†
 Cost of evaluating a patient for HAPI$2.762.35 to 3.17 25
 Cost of a stage 3, 4 or unstageable HAPI$6209.535278.10 to 7140.96 34 35
 Cost of an inpatient hospital stay$2122.531804.15 to 2440.91 15
 Cost of prevention (total)$99.4484.52 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$132.38112.52 to 152.24 25
QALYs
 Utility of an inpatient0.8270.703 to 0.951 15
 Utility of a HAPI0.5970.507 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 discharge13.2311.24 to 15.21 15
Probabilities
 Initial probability very high risk (Braden 6–9)0.07330.0623 to 0.0843Original data
 Initial probability high risk (Braden 10–12)0.01860.0158 to 0.0214Original data
 Initial probability moderate risk (Braden 13–14)0.12160.1034 to 0.1398Original data
 Initial probability at risk (Braden 15–18)0.29880.2540 to 0.3436Original data
 Initial probability minimal risk (Braden 19–23)0.48770.4145 to 0.5609Original data
 Probability of death after a stage III/IV HAPI0.07230.0615 to 0.0831 15
 Probability of death from surgery0.0000120.000010 to 0.000014 15
 Probability of acute and chronic care0.160.14 to 0.18 15
 Probability of surgery0.770.65 to 0.88 15
Odds ratios
 OR of HAPI incidence after prevention0.3350.285 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.