Table 2.
Diet and Exercise Characteristics
| Parameters | Data Source | |||
|---|---|---|---|---|
| Percent reduction in BMI | Probability of BMI reduction | Percent reduction in WOMAC Pain: Mean (SD) | Probability of weight loss failure (subsequent years) | |
| 20-25% | 0.08 | 52.1 (40.3) | 0.04 | Derived from IDEA trial datasets |
| 15-20% | 0.11 | 42.6 (53.1) | 0.04 | |
| 10-15% | 0.23 | 27.5 (51.6) | 0.04 | |
| 5-10% | 0.29 | 27.5 (51.6) | 0.34 | |
| 0% | 0.30 | 11.9 (44.6) | NA | |
| Probability of pain reduction failure (subsequent years)) | ||||
| Given weight loss success | 0.21 | |||
| Given weight loss failure | 0.57 | |||
| Discontinuation | ||||
| Overall Discontinuationa, b | 8% [12%, 16%] | |||
| Discontinuation due to Treatment Failurea | 0% [50%, 100%] | |||
| Duration of D+Ea | 2 years [3, 5, 8 years, no limit] | |||
| Cost | First Year | Subsequent Years | Derived from IDEA trial datasets, GNC Inc. (40) | |
| Personnel | $328 | $281 | ||
| Meal Replacementsa | $455 [0] | $0 | ||
| Gym Membershipa | $600 [$0] | $600 [$0] | Assumption | |
Abbreviations: SD, standard deviation; BMI, body mass index; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index.
a
Values in brackets were assessed in one-way sensitivity analyses
b
In the base case, we assumed that the D+E program would run for two years; thus, overall discontinuation only occurred in the first year. In sensitivity analyses, we tested longer durations of the D+E program and in those instances, the probability of discontinuation is annual.