A sub-group analysis of the Australian Multiple Sclerosis Longitudinal Study (AMSLS) assessing costs and utility in Primary Progressive Multiple Sclerosis (PPMS) patients

Primary Progressive Multiple Sclerosis (PPMS) is characterised by continuous neurological worsening from the first onset of symptoms, without remission or relapse. PPMS affects 10-15% of people diagnosed with Multiple Sclerosis (MS) and remains a severely disabling condition with no approved treatments. While a range of effective options are available for Relapsing and Remitting MS, only now are new treatments becoming available for PPMS. This report presents estimates of costs of PPMS in Australia by disability level, and assesses the impact of disability level on quality of life (QoL) and health state utility values (HSUVs) using data from Australian Multiple Sclerosis Longitudinal Study (AMSLS). The data presented in this report is aimed to inform Roche’s Pharmaceutical Benefits Advisory Committee (PBAC) submission.

Whilst the cost analysis presented here was based on data from 39 people with PPMS, QoL/HSUV analysis utilised data from 108 people with PPMS. We have segregated the costs and QoL/HSUV estimates in this report by disability severity (classified as mild, moderate, and severe), and Expanded Disability Status Scale (EDSS). As EDSS was mapped from the Patient Determined Disease Steps (PDDS), it was not possible to achieve an accurate estimate of costs and HSUVs by each single EDSS category, so we grouped some EDSS categories together (e.g.: 0-1, 2-3.5, 4-5).

The estimated costs per person with MS in 2017 Australian Dollars was $56,099 (95% confidence interval [CI]: 41,330–70,867), with indirect costs due to lost wages being the largest cost component (57%). The costs of PPMS generally exhibited an increasing trend with increasing disability severity/EDSS. The mean HSUV score (on a scale of 0-1) for all people with PPMS was 0.48 (95% confidence interval [CI]: 0.44−0.51), compared to 0.87 for the Australian general population. The mean QoL score (out of a maximum of 20) was 12.27 (physical health), 13.61 (psychosocial health), 11.91 (level of independence), 13.66 (social relationships), 15.04 (environment), and 12.83 (spirituality/religion/personal beliefs). As expected, the estimated QoL/HSUV scores generally declined with increasing disease severity/EDSS. Our results should however be interpreted with caution due to small sample sizes.