Richard Milne

Objectives Multiple sclerosis (MS) is a progressive, degenerative, autoimmune neuronal disease. This study compares the impact of a societal versus a healthcare perspective on the cost effectiveness of treatment of primary progressive MS (PPMS) with ocrelizumab (OCR) versus best supportive care (BSC) in New Zealand. Methods The analysis utilises a lifetime cohort Markov model based on ten Expanded Disability Status Scale (EDSS) states, plus death. It has two structurally identical arms, with forward transition probabilities in the treatment arm obtained by multiplying forward transition probabilities (converted to rates, and back to probabilities) in the control arm by the 12-week disability progression hazard ratio in the clinical trial ORATORIO. Direct and indirect costs of MS were estimated from a 2017 Australian survey and converted to 2024 NZ dollars using purchasing power parity and the NZ consumer price index. Future costs and benefits were discounted at 3.5% per annum. The model is calibrated to NZ mortality for PPMS, and therapy ends when wheelchair dependence (EDSS7) is reached. Results For a modelled cohort 40 years of age starting at the ORATORIO distribution of EDSS, at 50% of the list price (viz. 50% rebate on $NZ37,384 per patient per annum), the incremental cost-effectiveness ratio (ICER) of OCR versus BSC is $NZ114,427 per QALY ($US64,651) from a societal perspective or $NZ146,711 ($US82,892) from a healthcare perspective. From a societal perspective, at Treasury’s willingness to pay (WTP) criterion of $NZ120,200, an acquisition cost up to 56% of list price ($NZ20,935; 44% rebate) is justifiable. From a healthcare payer perspective, at Treasury’s implied WTP of $NZ43,313, an acquisition cost up to 10% of list price ($NZ3738; 90% rebate) is justifiable. Based on this metric, a 5.6-fold higher investment in OCR can be justified from a societal perspective compared with a healthcare perspective. Alternatively, an acquisition cost up to 37.9% of list price (viz. 62.1% rebate or $NZ14,169) could be justified if the criterion of one GDP per capita ($NZ83,011) is used as a societal funding threshold. These results are sensitive to the cost of BSC from a societal perspective but not from a healthcare perspective. From both perspectives the cost effectiveness is sensitive to the acquisition cost and efficacy of OCR, potential waning of efficacy, the age and EDSS state when therapy begins, the cost and timing of entry of a biosimilar pharmaceutical and the discount rate. Conclusions Treatment of PPMS with OCR is more cost effective from a societal than a healthcare perspective, therefore prioritisation of public funding of novel pharmaceuticals for MS and other resource intensive chronic health conditions will depend critically upon the study perspective.

Corrigendum for the article Hospital Cost Savings for Sequential COPD Patients Receiving Domiciliary Nasal High Flow Therapy

Purpose: To estimate the 5-year budget impact to Aotearoa New Zealand (NZ) hospitals of domiciliary nasal high flow (NHF) therapy to patients with chronic obstructive pulmonary disease (COPD) who require long term oxygen therapy. Methods: Hospital admission counts along with length of stay were obtained from hospital records of 200 COPD patients enrolled in a 12-month randomized clinical trial of NHF in Denmark, both over a 12-month baseline and then in the study period while on randomized treatment (control or NHF). NZ costings from similar COPD patients were estimated using data from Middlemore Hospital, Auckland and were applied to the Danish trial. The budget impact of NHF was estimated over the predicted 5-year lifetime of the device when used by patients sequentially. Results: Fifty-five of 100 patients in the NHF group and 44 of 100 patients in the control group were admitted to hospital with a respiratory diagnosis during the baseline year. They had 108 admissions in the treatment group vs 89 in the control group, with 632 vs 438 days in hospital, and modeled annual costs of $9443 vs $6512 per patient, respectively. During the study period there were 38 vs 44 patients with 67 vs 80 admissions and 302 vs 526 days in hospital, at a modeled annual cost of $6961 vs $9565 per patient respectively. Taking into account capital expenditure and running costs, this resulted in cost savings of $5535 per patient-year (95% CI, -$36 to -$11,034). With 90% usage over the estimated five-year lifetime of the NHF device, amortized capital costs of $594 per year and annual running costs of $662, we estimate a 5-year undiscounted cost saving per NHF device of $18,626 ($16,934 when discounted to net present value at 5% per annum). There would still be annual cost savings over a wide range of assumptions. Conclusion: Domiciliary NHF therapy for patients with severe COPD has the potential to provide substantial hospital cost savings over the five-year lifetime of the NHF device.

To establish the population-level predictive validity of the Framingham Heart Study risk equation used to derive cardiovascular disease risk-prediction charts for New Zealand management guidelines on raised blood pressure and dyslipidaemia. During 1992-3, standard cardiovascular risk factors were measured in a cohort of 6354 people (4638 men and 1716 women) aged 35-74 years with no history of cardiovascular disease, who were either enrolled on Auckland general electoral rolls or employed by a nationwide multi-industry corporation. Five-year cardiovascular event rates were predicted for the cohort using a Framingham risk equation and were compared with observed five-year cardiovascular event rates for hospitalisation and mortality. Incident cardiovascular hospitalisations or death were reported for 411 cohort participants (325 men and 86 women) during five years of follow up. There was good agreement between observed and predicted five-year cardiovascular event rates in all five-year age/sex categories up to 69 years. The risk equation tended to underestimate risk slightly in men and overestimate risk slightly in women up to 69 years, while in 70- to 74-year-olds it was accurate for men. Its accuracy in older women is uncertain. A Framingham Heart Study risk equation used to estimate incident cardiovascular events in individuals without previous cardiovascular disease accurately predicts five-year risk of hospitalisation or death from a first cardiovascular event in New Zealand men aged 35-74 and women aged 35-69 years at the population level.

To compare the discriminative ability of a multivariate risk-prediction model with individual continuous cardiovascular risk factors in a free-living population. Standard cardiovascular risk factors were measured in 6354 participants (4638 men and 1716 women) aged 35 to 74 years with no history of cardiovascular disease either enrolled on Auckland general electoral rolls or employed by a New Zealand-wide multi-industry corporation, in 1992-3. The sensitivity and specificity of individual risk factors versus a five-year cardiovascular risk-prediction equation and the corresponding New Zealand risk charts in predicting hospitalisation and mortality from cardiovascular disease in the subsequent five-year period were estimated over a range of risk thresholds. Discrimination between individuals who had or did not have subsequent cardiovascular events was poor for individual risk factors. Increasing age had significantly more discriminability than blood pressure or lipids and the Framingham Heart Study risk tool had better discriminability than any single risk factor. A Framingham risk equation and corresponding New Zealand risk charts discriminate between individuals who will or will not experience hospitalisation or death from cardiovascular events. Discriminability is only modest but it is better than that achieved using individual risk factors.