Sustainable medical expense has attracted public attention in rapidly aging societies. In fact, with a limited budget, the government of Japan has responded to increasing medical needs by lowering medical treatment fees and tightening regulations on hospital bed utilization. However, with information asymmetry between patients and medical professionals, "supplier-induced demands" -the phenomenon of increased medical service consumption caused by increased market competition -, has the potential to cancel the government's efforts. Supplier-induced demands can be seen when the number of medical institutions per capita is large (i.e., the market is competitive). Using Japanese data, this paper investigates whether or not the number of medical institutions per capita affects regional medical expense. Several researchers have investigated the phenomena by analyzing only macro and receipt data from Japan, without considering the details of patients' backgrounds. The current research addresses the absence of studies that include patient attributes. The study used detailed data, such as age, gender, health awareness, and annual income from Osaka University's Preference Parameter Study in Japan, as control variables to analyze the correlation between the number of medical institutions per capita and regional medical expense. Two-part model allowed separate investigations of consultation rates and costs per consultation. The results showed that, although market competitiveness positively affected consultation rates and negatively affected the cost per consultation, it did not significantly affect overall medical expense. The paper concludes that, even under conditions controlling detailed patient attributes, supplier-induced demands were not evident in the Japanese market.

The Central Social Insurance Medical Council is considering whether to use Quality Adjusted Life Years (QALY) as one of effectiveness indicator in evaluating cost effectiveness of medical technologies in health insurance coverage.

Rehabilitation is included among medical technologies, but there exist few reports on the cost effectiveness of rehabilitation. Also, while the inspection of measurement attributes is being actively carried out overseas in terms of utility measurement, in Japan there is uncertainty concerning measurement attributes. When calculating QALY using utility measurement, it is considered important to use the measurement on the basis of its attributes. In the present study, we analyzed item response theory (IRT) in Health Utilities Index Mark 3 (HUI3) for patients who underwent rehabilitation and investigated the measurement attributes of the Japanese version of HUI3.

The subjects were 412 cerebrovascular disease (CVD) patients admitted to six hospitals. HUI3 scores were: global score 0.05, vision 0.83, hearing 0.84, speech 0.67, ambulation 0.29, dexterity 0.55, emotion 0.65, cognition 0.49 and pain 0.76, showing.

Low levels for ambulation, dexterity and cognition. The discrimination by the IRT analysis was vision 0.99, hearing 1.36, speech 2.37, ambulation 2.89, dexterity 2.17, emotion 1.70, cognition 2.68 and pain 1.75,.

Showing high levels for ambulation and cognition, and low levels for vision and hearing. The difficulty by the IRT analysis showed low levels in vision (-2.91－-0.68) and hearing (-1.94－-1.13) and a high level in ambulation (-0.40－-1.45). The difficulty levels were slightly low for speech (-1.13－-0.51) and pain (-2.03－-0.98), and slightly high for dexterity (-1.06－-1.28), emotion (-2.61－-3.42) and cognition (-0.89－-1.21).

Regarding the overall measurement attributes of HUI3, the discrimination and information were high in a wide range of health states, with the highest information for subjects with somewhat higher health states. We found the evaluation by HUI3 in patients with CVD was useful in a wide range of health states, and most useful in subjects who had high health states. It was suggested that measurement with HUI3 was very useful in CVD patients because discrimination and information were particularly high in ambulation, dexterity and cognition in which disorders are common among these patients.