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.     

Identifying the sources of energy use change: Multiple calibration decomposition analysis and structural decomposition analysis

Decomposition methodologies are requisite to identify the sources of changes in energy use or carbon dioxide emissions. This paper is an inquiry into the theoretical properties of such decomposition methodologies. The study first presents our new decomposition methodology – the Multiple Calibration Decomposition Analysis (MCDA) – as a tool for the investigation. Then, it theoretically reexamines an established decomposition methodology – the Structural Decomposition Analysis proposed by Casler and Rose (1998). Subsequently, the study empirically investigates the properties of both methodologies, applying them to an actual case: the changes in energy use and carbon dioxide emissions in Japan during the oil crises period, when the oil price had a significant influence on the economy. The result shows that understanding the theoretical properties of decomposition methodologies is essential for a precise interpretation of empirical results.     

A flexible dynamic model of multiproduct technology for the West German economy

This paper tests symmetry and negativity of the Slutsky matrix for a system of demand functions derived from an aggregate model of multi product technology within a flexible dynamic framework. The model considers three inputs and three outputs, including imports and exports of intermediate goods. We derive a static demand model from a trans log cost function and specify the data generation process by a stationary ARX (1, 1) model. Results based on West German quarterly data indicate that the integrability conditions are not rejected when imposed on the ARX (1, 1) model, whereas they are rejected for all the less general dynamic models considered.     

Price competition in the spatial real estate market: allies or rivals?

This paper examines whether real estate firms can avoid price competition when properties in the vicinity are priced by allies. An oligopoly model with differentiated products generally suggests that real estate firms engage in price competition with their spatially closest rivals. Yet, they can raise property prices when the market share of their allies increases. To test this prediction, a spatial autoregressive model with spatial autoregressive disturbances, including a share of allies in the vicinity, is estimated using data on the prices of residential condos in central Tokyo, Japan. The model prediction is supported by the empirical results. In the data set, the magnitude of the market share on property prices increases with the expansion of the size of the spatial market.     

Empirical study on the determinants of CO2 emissions: evidence from OECD countries

This article empirically investigates the Environmental Kuznets Curve (EKC) for CO₂ emissions in the cases of 11 OECD countries by taking into account the role of nuclear energy in electricity production. The autoregressive distributed lag approach to cointegration is employed as the estimation method. Our results indicate that energy consumption has a positive impact on CO₂ emissions in most countries in the study. However, the impact of trade is not statistically significant. The results provide evidence for the role of nuclear power in reducing CO₂ emissions only in some countries. Additionally, although the estimated long-run coefficients of income and its square satisfy the EKC hypothesis in Finland, Japan, Korea and Spain, only Finland's EKC turning point is inside the sample period of the study, providing poor evidence in support of the EKC hypothesis.