Developing a preference-based utility scoring algorithm for the Psoriasis Area Severity Index (PASI)

Abstract

Introduction: It is challenging to identify health state utilities associated with psoriasis because generic preference-based measures may not capture the impact of dermatological symptoms. The Psoriasis Area Severity Index (PASI) is one of the most commonly used psoriasis rating scales in clinical trials. The purpose of this study was to develop a utility scoring algorithm for the PASI.

Methods: Forty health states were developed based on PASI scores of 40 clinical trial patients. Health states were valued in time trade-off interviews with UK general population participants. Regression models were conducted to crosswalk from PASI scores to utilities (e.g. OLS linear, random effects, mean, robust, spline, quadratic).

Results: A total of 245 participants completed utility interviews (51.4% female; mean age?=?45.3?years). Models predicting utility based on the four PASI location scores (head, upper limbs, trunk, lower limbs) had better fit/accuracy (e.g. R², mean absolute error [MAE]) than models using the PASI total score. Head/upper limb scores were more strongly associated with utility than trunk/lower limb. The recommended model is the OLS linear model based on the four PASI location scores (R²?=?0.13; MAE?=?0.03). An alternative is recommended for situations when it is necessary to estimate utility based on the PASI total score.

Conclusions: The derived scoring algorithm may be used to estimate utilities based on PASI scores of any treatment group with psoriasis. Because the PASI is commonly used in psoriasis clinical trials, this scoring algorithm greatly expands options for quantifying treatment outcomes in cost-effectiveness analyses of psoriasis therapies. Results indicate that psoriasis of the head/upper limbs could be more important than trunk/lower limbs, suggesting reconsideration of the standard PASI scoring approach.     

Within trial cost-utility analysis of disease management program for patients hospitalized with atrial fibrillation: results from the SAFETY trial

Abstract

Background: The potential impact of disease management to optimize quality of care, health outcomes, and total healthcare costs across a range of cardiac disease states is unknown.

Methods: A trial-based cost-utility analysis was conducted alongside a randomized controlled trial of 335 patients with chronic, non-valvular AF (without heart failure; the SAFETY Trial) discharged to home from three tertiary referral hospitals in Australia. A home-based disease management intervention (the SAFETY intervention) that involved community-based AF care including home visits was compared to routine primary healthcare and hospital outpatient follow-up (standard management). Bootstrapped incremental cost-utility ratios were computed based on quality-adjusted life-years (QALYs) and total healthcare costs. Cost-effectiveness acceptability curves were constructed to explore the probability of the SAFETY intervention being cost-effective. Sub-group analyses were performed based on age and sex to determine differential cost-effectiveness.

Results: During median follow-up of 1.75?years, the SAFETY intervention was associated with a non-statistically significant increase in QALYs (0.02 per person) and lower total healthcare costs (–$4,375 per person). Although each of these findings were not statistically significant, the SAFETY intervention was found to be dominant (more effective and cost saving) in 58.8% of the bootstrapped iterations and cost-effective (more effective and gains in QALYs achieved at or below $50,000 per QALY gained) in 61.5% of the iterations. Males and those aged less than 78?years achieved greater gains in QALYs and savings in healthcare costs. The estimated value of perfect information in Australia (the monetized value of removing uncertainty in the cost-effectiveness results) was A$51 million, thus demonstrating the high potential gain from further research.

Conclusions: Compared with standard management, the SAFETY intervention is potentially a dominant strategy for those with chronic, non-valvular AF. However, there would be substantial value in reducing the uncertainty in these estimates from further research.

Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12610000221055.     

Corporate structure,ownership and the likelihood of innovation

An examination is conducted into the effect which external ownership and other aspects of corporate ownership structure have on the likelihood of innovation for a sample of manufacturing plants located in Scotland. Econometric estimation indicates that plant size, the presence of in-plant R&D, and non-UK ownership have a positive effect on the likelihood of innovation. Multiplant operation, market power and variations in industrial structure have no discernible effect on innovation. The finding that foreign ownership is positively associated with innovation contrasts with previous research conducted on manufacturing plants in Northern Ireland.     

The Psychology of Billing

Contracting between tax entities and tax professionals occurs millions of times every year, yet little is known about the nature of these economic interactions. This study examines the effect of commonly occurring contextual factors on tax professionals’ billing decisions for tax research. These contextual factors are unrelated to the tax research itself and the time it takes to conduct the tax research, but we find that billing decisions are strongly influenced by the three non‐time‐related contextual factors that we manipulate. Initial client volume impacts amounts billed for tax research, with lower initial client volume resulting in higher per client fees. Further, we find that initial billing decisions serve as value billing benchmarks for unanticipated subsequent clients who benefit from research conducted for initial clients. As a result, subsequent clients are billed higher fees when they follow a smaller number of initial clients. We also find that client referrals are billed higher fees than nonclient referrals because professionals attempt to avoid making initial clients feel as though they have been treated unfairly relative to subsequent clients who would otherwise be billed lower fees. The results of this study are relevant beyond the traditional confines of accounting research—they are relevant to the millions of tax entities that contract with tax professionals each year.