Chris Schilling

Food prices and consumer demand: differences across income levels and ethnic groups.

Background Targeted food pricing policies may improve population diets. To assess their effects on inequalities, it is important to determine responsiveness to price changes across income levels and ethnic groups. Objective Our goal was to estimate price elasticity (PE) values for major commonly consumed food groups in New Zealand, by income and ethnicity. PE values represent percentage change in demand associated with 1% change in price of that good (own-PE) or another good (cross-PE). Design We used food expenditure data from national household economic surveys in 2007/08 and 2009/10 and Food Price Index data from 2007 and 2010. Adopting an Almost Ideal Demand System approach, own-PE and cross-PE estimates were derived for 24 food categories, household income quintiles, and two ethnic groups (Māori and non-Māori). Results Own-PE estimates (with two exceptions) ranged from −0.44 to −1.78. Cross-PE estimates were generally small; only 31% of absolute values were greater than 0.10. Excluding the outlier ‘energy drinks’, nine of 23 food groups had significantly stronger own-PEs for the lowest versus highest income quintiles (average regression-based difference across food groups −0.30 (95% CI −0.62 to 0.02)). Six own-PEs were significantly stronger among Māori; the average difference for Māori: non-Māori across food groups was −0.26 (95% CI −0.52 to 0.00). Conclusions Food pricing policies have potential to improve population diets. The greater sensitivity of low-income households and Māori to price changes suggests the beneficial effects of such policies on health would be greatest for these groups.

The Fontan epidemic: Population projections from the Australia and New Zealand Fontan Registry

BACKGROUND The number and age demographic of the future Fontan population is unknown. METHODS Population projections were calculated probabilistically using microsimulation. Mortality hazard rates for each Fontan recipient were calculated from survivorship of 1353 Fontan recipients in the Australia and New Zealand Fontan Registry, based on Fontan type, age at Fontan, gender and morphology. Projected rates of new Fontan procedures were generated from historical rates of Fontan procedures per population births. RESULTS At the end of 2014, the living Fontan population of Australia and New Zealand was 1265 people from an Australian and New Zealand regional population of 28 million (4.5 per 100,000 population). Of those, 165 (13%) received an atrio-pulmonary (AP) procedure, 262 (21%) a lateral tunnel (LT) procedure and 838 (66%) an extra-cardiac conduit (ECC) procedure. This population is expected to grow to 1917 (95% CI: 1846: 1986) by 2025 (5.8 per 100,000 population), with 149 (8%) AP procedures, 254 (13%) LT procedures, and 1514 (79%) ECC procedures. By 2045, the living Fontan population is expected to reach 2986 (95% CI: 2877: 3085; 7.2 per 100,000 population). The average age of the Fontan population is expected to increase from 18years in 2014 to 23years (95% CI: 22-23) by 2025, and 31years (95% CI: 30-31) by 2045. CONCLUSION The Australian and New Zealand population of patients alive after a Fontan procedure will double over the next 20years increasing the demand for heart-failure services and cardiac transplantation. Greater consideration for the needs of this mostly adult Fontan population will be necessary.

Use of ACE inhibitors in Fontan: Rational or irrational?

BACKGROUND Despite a lack of evidence supporting the use of angiotensin-converting enzyme (ACE) inhibitors in patients with a Fontan circulation, their use is frequent. We decided to identify the rationale for ACE inhibitor therapy in patients within the Australia and New Zealand Fontan Registry. METHODS All patients in the Registry taking an ACE inhibitor at last follow up were identified, and a review of medical records was undertaken to determine the rationale for treatment initiation and reasons for treatment continuation or dose increase. RESULTS In 2015, 36% of the surviving patients in the Registry (462/1268) were taking an ACE inhibitor. Indications for initiation of therapy were ventricular systolic or diastolic dysfunction (29%), atrioventricular valve regurgitation (19%), preservation of normal ventricular function (7%), prolonged effusions at Fontan (6%), hypertension (6%), other (6%) and unknown (2%). No indication was stated in the remaining patients (25%). Those with hypoplastic left heart syndrome were more likely to be on an ACE inhibitor than those with an alternative primary morphology (70% vs 32%; p<0.001). Only 36% of the patients treated with an ACE inhibitor at last follow up (166/462) had an indication that would generally justify treatment in a two-ventricle circulation. CONCLUSION It is likely that the use of ACE inhibitors in patients with a Fontan circulation is excessive within our region. The coordination of prospective, multicentre studies and initiatives such as the Australia and New Zealand Fontan Registry will facilitate further investigations to guide treatment decisions in the growing Fontan population.

Revisiting the “Christmas Holiday Effect” in the Southern Hemisphere

Background A “Christmas holiday effect” showing elevated cardiovascular mortality over the Christmas holidays (December 25 to January 7) was demonstrated previously in study from the United States. To separate the effect of seasonality from any holiday effect, a matching analysis was conducted for New Zealand, where the Christmas holiday period falls within the summer season. Methods and Results New Zealand mortality data for a 25‐year period (1988–2013) was analyzed based on the same methodology used in the previous study. Locally weighted smoothing was used to calculate an “expected” number of deaths for each day of the year. The expected value was compared with the actual number of deaths. In addition, mean age at death was estimated and used to assess the life‐years lost due to excess mortality. There were 738 409 deaths (197 109 coded as cardiac deaths) during the period. We found evidence of a Christmas holiday effect in our of medical facilitys cardiac deaths, with an excess event rate of 4.2% (95% CI 0.7–7.7%) leading to ≈4 additional deaths per annum. The average age of those with fatal cardiac deaths was 76.8 years (SD 13.5) during the Christmas holiday period, resulting in 148 to 222 years of life lost per annum. Conclusions Cardiac mortality is elevated during the Christmas holiday period relative to surrounding time periods. Our findings are consistent with a previously reported study conducted in the United States, suggesting that cardiac mortality does not take a “summer break.”

The economic impact of the New Zealand fiscal stimulus package

Unlike many countries affected by the global financial crisis, New Zealand did not announce a formal fiscal stimulus package. However, via a series of policy announcements beginning in October 2008, by March 2009 the government budget balance had moved towards deficit by 1.6% of 2011 GDP. We interpret this discretionary movement towards deficit as New Zealands fiscal stimulus package. The package largely comprises three policies: cuts to personal income taxes, cuts to business taxes, and infrastructure spending. We investigate the individual and joint effects of these policies using a dynamic CGE model of the New Zealand economy. We find that the package has a small positive effect on short-run employment, but at a cost to long-run real consumption. We examine an alternative package, which generates a larger short-run employment gain, for a similar long-run real consumption cost.

Using CART to Identify Thresholds and Hierarchies in the Determinants of Funding Decisions

There is much interest in understanding decision-making processes that determine funding outcomes for health interventions. We use classification and regression trees (CART) to identify cost-effectiveness thresholds and hierarchies in the determinants of funding decisions. The hierarchical structure of CART is suited to analyzing complex conditional and nonlinear relationships. Our analysis uncovered hierarchies where interventions were grouped according to their type and objective. Cost-effectiveness thresholds varied markedly depending on which group the intervention belonged to: lifestyle-type interventions with a prevention objective had an incremental cost-effectiveness threshold of

The Cost Differential Between Warfarin Versus Aspirin Treatment After a Fontan Procedure

2356, suggesting that such interventions need to be close to cost saving or dominant to be funded. For lifestyle-type interventions with a treatment objective, the threshold was much higher at

The Impact of Regression to the Mean on Economic Evaluation in Quasi-Experimental Pre–Post Studies: The Example of Total Knee Replacement Using Data from the Osteoarthritis Initiative

37,024. Lower down the tree, intervention attributes such as the level of patient contribution and the eligibility for government reimbursement influenced the likelihood of funding within groups of similar interventions. Comparison between our CART models and previously published results demonstrated concurrence with standard regression techniques while providing additional insights regarding the role of the funding environment and the structure of decision-maker preferences.

Predictors of inpatient rehabilitation after total knee replacement: an analysis of private hospital claims data

BACKGROUND The use of aspirin versus warfarin for treatment of patients after a Fontan procedure remains contentious. Current preference-based models of treatment across Australia and New Zealand show variation in care that is unlikely to reflect patient differences and/or clinical risk. METHODS We combine data from the Australian and New Zealand Fontan Registry and a home INR (International Normalised Ratio) monitoring program (HINRMP) from the Royal Childrens Hospital (RCH) Melbourne, to estimate the cost difference for Fontan recipients receiving aspirin versus warfarin for 2015. We adopt a societal perspective to costing which includes cost to the health system (e.g. medical consults, pathology tests) and costs to patients and carers (e.g. travel and time), but excludes costs of adverse events. Costs are presented in Australian 2015 dollars; any costs from previous years have been inflated using appropriate rates from the Australian Bureau of Statistics. RESULTS We find that warfarin patients face additional costs of

Using Patient-Reported Outcomes for Economic Evaluation: Getting the Timing Right

825 per annum, with the majority (