Psychometric validation of anti-clot treatment scale and treatment satisfaction questionnaire for medication version II in Japanese patients with atrial fibrillation

Aims: The Anti-Clot Treatment Scale (ACTS) and Treatment Satisfaction Questionnaire for Medication version II (TSQM-II) are validated treatment satisfaction patient-reported outcome (PRO) instruments. The ACTS includes two domains: Burdens and Benefits; the TSQM-II includes four: Effectiveness, Side Effects, Convenience, and Global Satisfaction. Japanese-language versions of the ACTS and TSQM-II have been developed and linguistically validated. This study aimed to assess their psychometric properties in Japanese patients with atrial fibrillation (AF).

Materials and methods: ACTS and TSQM-II data from 534 patients with AF were collected in a Japanese post-marketing surveillance study of a direct oral-anticoagulant, rivaroxaban. Four key psychometric properties, in line with best practice guidelines from the US Food and Drug Administration, were examined using traditional psychometric methods: acceptability, scaling assumptions, reliability (i.e. internal consistency reliability, test-retest reliability), and construct validity (i.e. convergent validity and known groups).

Results: ACTS Burdens and Benefits and TSQM-II Effectiveness, Convenience, and Global Satisfaction scales were found to be acceptable (e.g. item-level missing data at baseline <4%), with all scales having good internal consistency (Cronbach’s alpha > 0.80). test-retest reproducibility intraclass correlation coefficients for the ACTS Burdens and Benefits were 0.59 and 0.65, respectively, and between 0.54–0.61 for the TSQM-II scales. Known-groups validity for the ACTS and TSQM-II was supported by differences in scale scores by positive and negative impact (p?<?0.05). Correlations between the ACTS and TSQM-II (convergent validity) were lower than expected (range r?=?0.09–0.48), but in line with the original ACTS development study.

Limitations: Evaluation of test-retest reproducibility was limited by assessment period, which was longer (3 months) than recommended guidelines (usually up to 2 weeks).

Conclusions: Overall, Japanese versions of ACTS and TSQM-II scales satisfied internal consistency reliability and traditional validity criteria. Our study supports the ACTS and TSQM-II as appropriate PRO instruments to measure satisfaction with anticoagulant treatment in Japanese patients with AF.

Trial registration: NCT01598051, clinicaltrials.gov; registered April 20, 2012.     

Adverse Selection and the Decline in Private Health Insurance Coverage in Australia: 1989–95

The decline in private health insurance coverage over the period 1989–95 is analysed using the ABS National Health Surveys. Individuals' health status and health risk behaviours are found to be significant determinants of their decision to purchase private health insurance. At a point in time, the pool of the insured is very heterogeneous, with a mix of both good and bad health risks. It is found that the decline in insurance coverage over the period 1989–95 coincided with an increase in the degree of 'adverse selection' within the insured population.     

Risk-aversion and the term structure of real interest rates

The term structure of real interest rates is studied in the context of a consumption-based general-equilibrium model. It is shown that the expectations hypothesis is approximately satisfied for low interest rate volatility. Otherwise the term premia are generally positive.     

The Effects of Future Capital Investment and R&D Expenditures on Firms' Liquidity

The paper explores factors that lead to accumulation or decumulation of firms' cash reserves. In particular, the paper empirically examines whether additional future fixed capital and R&D investment expenditures induce firms to change their liquidity ratio while considering the role of market imperfections. Implementing a dynamic framework on a panel of US, UK, and German firms, it is found that firms in all three countries make larger adjustments to cash holdings when they plan additional future R&D rather than fixed capital investment expenditures. This behavior is particularly prevalent among financially constrained firms.     

FISCAL ILLUSION (THE FLYPAPER EFFECT) AND GOVERNMENT SPENDING IN AUSTRALIA*

Work in the US and Canada has found the flypaper effect to be evident at the national as well as the sub-national government level. This paper uses the methodology developed by Robert R. Logan (1986) to examine how the payment of inter-governmental grants has affected government expenditure in Australia. The analysis is of both the recipient and payee governments.     

On adding over-identifying instrumental variables to simultaneous equations

Reducing the number of over-identifying instruments, or adding them to a structural equation, increases estimation dispersion. Added instruments should be insignificant under correct specification, with parameter estimates nearly unaffected, confirmed by Monte Carlo. Selecting instruments does not affect these results.     

Einzelbesprechungen

Ohne ZusammenfassungAus dem Italienischen übersetzt von M. St. Braun, WienAus dem Italienischen übersetzt von E. Allina, WienAus dem Russischen übersetzt von A. GerschenkronÜbersetzt von Paul Brüll, Wien.