Table 2.
Model Results for Natural History of HD
| aPrefunctional decline population | Shoulson and Fahn stage 1 population | Shoulson and Fahn stage 2 population | ||||
| Base case | 95% credible range | Base case | 95% credible range | Base case | 95% credible range | |
| Discounted (3% annually) outcomes | ||||||
| Total costs | $508,185 | $310,322 to $803,738 | $1,148,001 | $684,463 to $1,890,836 | $1,074,852 | $571,656 to $2,261,835 |
| Standard care | $126,658 | $74,000 to $203,425 | $286,932 | $166,641 to $498,574 | $258,505 | $129,220 to $551,468 |
| Shoulson and Fahn stage 1 | $18,960 | $8,712 to $38,018 | $38,836 | $18,472 to $82,347 | — | — |
| Shoulson and Fahn stage 2 | $39,340 | $11,851 to $98,648 | $84,221 | $25,233 to $222,523 | $69,631 | $20,493 to $264,494 |
| Shoulson and Fahn stage 3 | $36,168 | $12,221 to $82,408 | $83,656 | $28,898 to $190,609 | $95,754 | $28,613 to $251,721 |
| Shoulson and Fahn stage 4–5 | $32,189 | $13,403 to $58,582 | $80,219 | $34,694 to $151,660 | $93,120 | $31,316 to $188,030 |
| Societal cost | $381,527 | $203,487 to $659,313 | $861,069 | $442,721 to $1,541,503 | $816,347 | $382,772 to $1,845,534 |
| Shoulson and Fahn stage 1 | $44,140 | $16,606 to $97,709 | $90,411 | $35,792 to $204,997 | — | — |
| Shoulson and Fahn stage 2 | $99,074 | $41,222 to $206,498 | $212,104 | $89,412 to $446,572 | $175,360 | $67,452 to $611,320 |
| Shoulson and Fahn stage 3 | $197,317 | $83,990 to $389,646 | $456,388 | $180,050 to $930,370 | $522,390 | $191,413 to $1,232,080 |
| Shoulson and Fahn stage 4–5 | $40,996 | $2,747 to $199,446 | $102,165 | $7,005 to $491,406 | $118,596 | $6,641 to $583,754 |
| Total QALYs | 15.93 | 14.91 to 17.44 | 8.29 | 6.36 to 11.79 | 5.79 | 4.14 to 12.91 |
| Prefunctional decline | 12.11 | 11.81 to 12.60 | — | — | — | — |
| Shoulson and Fahn stage 1 | 1.13 | 0.83 to 1.72 | 2.31 | 1.67 to 3.76 | — | — |
| Shoulson and Fahn stage 2 | 1.57 | 1.21 to 2.09 | 3.35 | 2.53 to 4.91 | 2.77 | 1.90 to 8.33 |
| Shoulson and Fahn stage 3 | 0.97 | 0.80 to 1.11 | 2.25 | 1.76 to 2.84 | 2.57 | 1.81 to 4.30 |
| Shoulson and Fahn stage 4–5 | 0.15 | 0.08 to 0.23 | 0.38 | 0.20 to 0.58 | 0.44 | 0.20 to 0.72 |
| Total life years | 20.46 | 19.05 to 22.30 | 13.93 | 10.82 to 19.08 | 10.99 | 8.28 to 22.07 |
| Undiscounted outcomes | ||||||
| Total costs | $1,036,543 | $605,715 to $1,696,369 | $1,547,533 | $857,986 to $2,982,127 | $1,319,022 | $654,363 to $3,577,753 |
| Standard care | $258,686 | $149,724 to $429,579 | $389,033 | $213,816 to $735,896 | $322,687 | $155,796 to $858,465 |
| Shoulson and Fahn stage 1 | $31,779 | $14,418 to $67,388 | $40,322 | $18,223 to $86,478 | — | — |
| Shoulson and Fahn stage 2 | $73,329 | $22,107 to $185,441 | $99,912 | $30,590 to $276,835 | $73,726 | $20,550 to $335,615 |
| Shoulson and Fahn stage 3 | $77,382 | $25,203 to $171,617 | $118,639 | $40,640 to $295,642 | $118,028 | $34,886 to $366,745 |
| Shoulson and Fahn stage 4–5 | $76,196 | $32,714 to $142,244 | $130,160 | $54,658 to $278,364 | $130,933 | $44,442 to $327,548 |
| Societal cost | $777,857 | $401,087 to $1,402,095 | $1,158,500 | $554,107 to $2,415,677 | $996,334 | $427,038 to $2,883,906 |
| Shoulson and Fahn stage 1 | $73,982 | $28,437 to $168,350 | $93,869 | $36,011 to $221,717 | — | — |
| Shoulson and Fahn stage 2 | $184,673 | $77,807 to $406,172 | $251,619 | $104,449 to $592,225 | $185,672 | $71,806 to $769,436 |
| Shoulson and Fahn stage 3 | $422,160 | $172,554 to $863,018 | $647,243 | $256,740 to $1,465,711 | $643,908 | $225,247 to $1,885,819 |
| Shoulson and Fahn stage 4–5 | $97,042 | $6,688 to $459,831 | $165,769 | $11,591 to $875,066 | $166,754 | $9,200 to $940,510 |
| Total QALYs | 24.53 | 22.41 to 28.18 | 10.18 | 7.29 to 16.78 | 6.73 | 4.56 to 20.51 |
| Prefunctional decline | 17.28 | 16.82 to 18.05 | — | — | — | — |
| Shoulson and Fahn stage 1 | 1.89 | 1.36 to 3.07 | 2.40 | 1.69 to 4.10 | — | — |
| Shoulson and Fahn stage 2 | 2.92 | 2.14 to 4.33 | 3.98 | 2.82 to 6.74 | 2.94 | 1.98 to 10.79 |
| Shoulson and Fahn stage 3 | 2.08 | 1.59 to 2.60 | 3.19 | 2.28 to 5.07 | 3.17 | 2.08 to 8.04 |
| Shoulson and Fahn stage 4–5 | 0.36 | 0.19 to 0.55 | 0.61 | 0.32 to 1.07 | 0.62 | 0.28 to 1.32 |
| Total life years | 32.52 | 29.27 to 37.64 | 17.82 | 12.89 to 28.43 | 13.17 | 9.35 to 37.36 |
Abbreviations: QALY = quality-adjusted life year; TFC = total functional score.
a
Prefunctional decline population: age = 40, CAG repeats = 40; results for prefunctional decline individuals with 45 and 50 CAG repeats are available in eAppendix 1.