Online Resource 1

Meta-analysis of relative risk of hip fracture with treatment

Fig 1 Relative risk of hip fracture with risedronate and alendronate in severe post-menopausal osteoporosis (bone mineral density 2.5 standard deviations or more below the young adult mean plus at least one document fracture) [1]

Health state utility for the general population in Canada

We estimated the general population utility score using growth models from a Canadian study (Fig2 shows how the utility of the general population declines as they age) [2]:

Health state utility of men by age = 0.926754 - 0.007832 * (age-40) + 0.000483 * (age-40)2 - 0.000011 * (age-40)3

Health state utility of women by age = 0.917889 - 0.011380 * (age-40) + 0.000664 * (age-40)2 - 0.000013 * (age-40)3

Fig2 Utility of the general population, as predicted by the growth models from the Canadian study [2]. From the growth models, the estimated utility after age 88 was less than 0.44,but the mean utility of those aged 90 years and above was 0.44 in the study [2]. We assumed patients had a utility of 0.44 when they reached 89 years old and above

Table 1 Deterministic sensitivity analysis, per patient

No. / Scenario / Number of hip fracture prevented / QALY gained (disc) / Additional cost (disc) / Incremental cost per QALY
Base case / 0.003 / 0.004 / $83 / $19,132
1 / Lower cost of program $50 vs. $97 / 0.003 / 0.004 / $36 / $8,368
2 / Higher cost of program $150 vs. $97 / 0.003 / 0.004 / $136 / $31,431
3 / Clinical outcomes discounted at 1.5% vs. 5% per year / 0.003 / 0.007 / $83 / $12,238
4 / Clinical outcomes discounted at 0% vs. 5% per year / 0.003 / 0.008 / $83 / $9,868
5 / Costs and outcomes discounted at 3% vs. 5% per year / 0.003 / 0.006 / $55 / $9,853
6 / Probability of receiving BMD test in usual care (8% vs. 3.9%) / 0.003 / 0.004 / $81 / $19,806
7 / Probability of receiving BMD test in usual care (15% vs. 3.9%) / 0.003 / 0.004 / $79 / $21,141
8 / Prevalence of low bone mass (67% vs. 83%) / 0.002 / 0.003 / $97 / $29,743
9 / Lower probability of 2nd hip fracture (1% vs. 1.4% per year) / 0.003 / 0.004 / $88 / $20,706
10 / Higher probability of 2nd hip fracture (2% vs. 1.4% per year) / 0.003 / 0.004 / $75 / $16,995
11 / Lower probability of 1st hip fracture (0.2% vs. 0.4% per year) / 0.002 / 0.002 / $177 / $76,428
12 / Higher probability of 1st hip fracture (0.6% vs. 0.4% per year) / 0.004 / 0.006 / ($7) / Dominant
13 / Lower treatment persistence (55% vs. 65%) / 0.002 / 0.004 / $95 / $25,885
14 / Higher treatment persistence (75% vs. 65%) / 0.003 / 0.005 / $71 / $14,172
15 / Treatment effect ends when treatment stops vs. another 5 years of effect / 0.002 / 0.003 / $158 / $58,704
16 / Treatment effect ends 10 years after treatment stops vs. 5 years after treatment / 0.004 / 0.005 / $43 / $8,159
17 / More effective treatment (relative risk of 0.45 vs. 0.57) / 0.004 / 0.006 / $26 / $4,741
18 / Less effective treatment (relative risk of 0.70 vs. 0.57) / 0.002 / 0.003 / $144 / $47,639
19 / Lower treatment cost ($50 vs. $161) / 0.003 / 0.004 / $11 / $2,593
20 / Higher treatment cost ($260 vs. $161) / 0.003 / 0.004 / $188 / $43,445
21 / Higher BMD test rates (60% vs. 45%) / 0.004 / 0.006 / $77 / $12,608
22 / Higher BMD test rates based on the BMD Fast Track Program (96% vs. 45%) / 0.007 / 0.010 / $60 / $5,740
23 / BMD fast track with no testing in hip fracture cohort (96% BMD test rate in non-hip, no BMD test (initial and follow-up) and 63% treatment rates in hip fracture cohort / 0.007 / 0.010 / $41 / $3,981
24 / No post hip fracture cost in hip fracture cohort until they have a 2nd hip fracture / 0.003 / 0.004 / $50 / $11,589
25 / Lower utility for the 1st year after hip fracture (0.64 vs. 0.70) / 0.003 / 0.004 / $83 / $18,715
26 / Higher utility for the 1st year after hip fracture (0.80 vs. 0.70) / 0.003 / 0.004 / $83 / $19,871
27 / Lowest utilities after hip fracture (0.64 during the 1st year and 0.68 after 1st year) / 0.003 / 0.005 / $83 / $15,668
28 / Highest utilities after hip fracture (0.80 during the 1st year and 0.90 after 1st year) / 0.003 / 0.003 / $83 / $24,000
29 / Cost of hip fracture (20% lower) / 0.003 / 0.004 / $124 / $28,553
30 / Cost of hip fracture (20% higher) / 0.003 / 0.004 / $42 / $9,712
31 / No bi-annual follow-up BMD test among patients who receive treatment / 0.003 / 0.004 / $83 / $19,132
32 / Utilities for the hip fracture cohort were the same as general population before the 2nd hip fracture / 0.003 / 0.005 / $83 / $17,645

Table 2 Scenario analysis changing key inputs to mirror another cost-effectiveness analysis of fracture liaison services [3]

Changing input / FCS (base case) / Estimates changed to mirror Majumdar 2013 [3]
BMD test rate / 45% / 16%
Treatment rate, intervention / 33% / 15%
Relative risk of hip fracture for bisphosphonates / 0.57 / 0.51
Cost of intervention / $97 / $7
Cost of test / $83 / $83
Discount rates / 5% / 3%
Post hip fracture cost in hip fracture cohort before 2nd hip fracture / $10,776 / 0
Post hip fracture utility in hip fracture cohort before 2nd hip fracture / 0.8 / 1
Incremental analysis (intervention vs. usual care) / FCS (base case) / Estimated from our model / Majumdar 2013[3]
Hip fracture avoided / 0.0030 / 0.0006 / 0.0006
QALY gained (disc) / 0.0043 / 0.0012 / 0.0017
Total cost (disc) / $83 / $(8) / $(22)
Incremental cost per QALY gained / $19,132 / Dominant / Dominant

Table 3 Costs and health outcomes per patient, BMD Fast Track program vs. usual care (all model input were set to mean values)

BMD Fast Track program / Usual care / Incrementalb
Number receive BMD test, per 1000 patients / 960 / 39 / 921
Number receive treatment, per 1000 patients / 650 / 106 / 543
Number of hip fracture, per 1000 patients / 65 / 72 / 7
Life-year / 17.193 / 17.169 / 0.023
QALY / 11.432 / 11.412 / 0.020
QALY (discounted)a / 7.4237 / 7.4134 / 0.0103
Program cost / $97 / $- / $97
BMD test cost / $171 / $15 / $156
Osteoporosis treatment cost / $409 / $67 / $342
Hip fracture cost / $15,863 / $16,614 / $(750)
Total cost / $16,541 / $16,696 / $(155)
Total cost (discounted)a / $11,351 / $11,292 / $59
ICER (Incremental cost per QALY, discounted)a / $5,720

aDiscounted at 5% per year

b Numbers in () are negative

References

1.MacLean C, Newberry S, Maglione M, et al. (2008) Systematic review: comparative effectiveness of treatments to prevent fractures in men and women with low bone density or osteoporosis. Ann Intern Med 148(3):197-213

2.Orpana HM, Ross N, Feeny D, McFarland B, Bernier J, Kaplan M (2009) The natural history of health-related quality of life: a 10 year cohort study. Statistics Canada, Ottawa, Ontario

3.Majumdar SR, Lier DA, Leslie WD (2013) Cost-effectiveness of two inexpensive postfracture osteoporosis interventions: results of a randomized trial. J Clin Endocrinol Metab 98(5):1991-2000