Contributions
Abstract: P730
Type: Poster
Abstract Category: Therapy - disease modifying - 28 Long-term treatment monitoring
Objectives:
(1) Estimate effects of exposure to first generation disease-modifying drugs (DMDs) - interferon β-1a IM, interferon β-1a SC, interferon β-1b, glatiramer acetate - on disability progression speed in relapsing-onset multiple sclerosis (R-onset MS);
(2) test hypothesis that marginal effects are larger when disability is milder, and diminish with years since exposure;
(3) estimate natural history (NH) paths, new natural history (NNH) paths and health outcomes;
(4) estimate cost-effectiveness;
(5) estimate costs avoided by stopping treatment when marginal effects approach zero.
Study design: An observational, population-based, retrospective, treatment intervention study from an intention-to-treat perspective, for study period 1979-2010.
Setting: Nova Scotia enacted universal zero-copay insurance coverage of DMDs for ambulatory definite R-onset MS patients in 1998.
Methods: MS disability is measured by Expanded Disability Status Scale (EDSS) and by Health Utility Index Mark III (HUI3). EDSS observations are adjusted for interval censoring. A fixed effect regression model estimates disability NH paths, NNH paths and marginal DMD exposure effects. Our reference treatment group and historical self-controls group includes 1,114 persons in ambulatory range EDSS 0-6.5; each person has a year of onset and pre- and post-DMD exposure observations. Health outcomes - as measured by edss-DALYs avoided and hui3-QALYs gained - are computed by area-under-the-curve methods. Nova Scotia costs per DMD treatment year are expressed as 2017 US dollars.
Results: Marginal effects are larger when disability at exposure is milder, and diminish with years since exposure. Marginal effects are significant in range EDSS 0-4.5 for patients who did not progress to SPMS. Health outcomes per person - as measured by edss-DALYs avoided (0.6) or hui3-QALYs gained (1.1) -- are modest. Cost/hui3-QALY gained diminishes to “C/E acceptability threshold” US $100,000 only after 25 years since onset, when cost per treatment year is US $12,191. Costs avoidable -- by stopping DMD treatment when marginal effects approach zero -- range from 30% (stop after conversion to SPMS) to 38% (and stop after EDSS 4.5) without loss of benefits.
Conclusions: Exposure to DMDs slows disability progression in range EDSS 0-4.5. Health outcomes are modest. DMDs may be cost-effective, given low DMD costs. Stopping treatment when marginal effects approach zero avoids costs without loss of benefits.
Disclosure:
Brown MG: nothing to disclose.
Hicks V: nothing to disclose.
Asbridge M: nothing to disclose.
Murray TJ: nothing to disclose.
Andreou P: nothing to disclose.
Abstract: P730
Type: Poster
Abstract Category: Therapy - disease modifying - 28 Long-term treatment monitoring
Objectives:
(1) Estimate effects of exposure to first generation disease-modifying drugs (DMDs) - interferon β-1a IM, interferon β-1a SC, interferon β-1b, glatiramer acetate - on disability progression speed in relapsing-onset multiple sclerosis (R-onset MS);
(2) test hypothesis that marginal effects are larger when disability is milder, and diminish with years since exposure;
(3) estimate natural history (NH) paths, new natural history (NNH) paths and health outcomes;
(4) estimate cost-effectiveness;
(5) estimate costs avoided by stopping treatment when marginal effects approach zero.
Study design: An observational, population-based, retrospective, treatment intervention study from an intention-to-treat perspective, for study period 1979-2010.
Setting: Nova Scotia enacted universal zero-copay insurance coverage of DMDs for ambulatory definite R-onset MS patients in 1998.
Methods: MS disability is measured by Expanded Disability Status Scale (EDSS) and by Health Utility Index Mark III (HUI3). EDSS observations are adjusted for interval censoring. A fixed effect regression model estimates disability NH paths, NNH paths and marginal DMD exposure effects. Our reference treatment group and historical self-controls group includes 1,114 persons in ambulatory range EDSS 0-6.5; each person has a year of onset and pre- and post-DMD exposure observations. Health outcomes - as measured by edss-DALYs avoided and hui3-QALYs gained - are computed by area-under-the-curve methods. Nova Scotia costs per DMD treatment year are expressed as 2017 US dollars.
Results: Marginal effects are larger when disability at exposure is milder, and diminish with years since exposure. Marginal effects are significant in range EDSS 0-4.5 for patients who did not progress to SPMS. Health outcomes per person - as measured by edss-DALYs avoided (0.6) or hui3-QALYs gained (1.1) -- are modest. Cost/hui3-QALY gained diminishes to “C/E acceptability threshold” US $100,000 only after 25 years since onset, when cost per treatment year is US $12,191. Costs avoidable -- by stopping DMD treatment when marginal effects approach zero -- range from 30% (stop after conversion to SPMS) to 38% (and stop after EDSS 4.5) without loss of benefits.
Conclusions: Exposure to DMDs slows disability progression in range EDSS 0-4.5. Health outcomes are modest. DMDs may be cost-effective, given low DMD costs. Stopping treatment when marginal effects approach zero avoids costs without loss of benefits.
Disclosure:
Brown MG: nothing to disclose.
Hicks V: nothing to disclose.
Asbridge M: nothing to disclose.
Murray TJ: nothing to disclose.
Andreou P: nothing to disclose.