Health economics evaluations are affected by uncertainty when estimating their parameters. Therefore, it is important that we use a sensitivity analysis to determine the robustness of these evaluations. Most countries' guidelines recommend using a probabilistic sensitivity analysis (PSA), which enables us to evaluate the uncertainty of multiple parameters at the same time, based on a joint probability distribution. In this article, we first introduce the Monte Carlo simulation and Bootstrap method as PSA methods. Then, we review how various guidelines incorporate the PSA. Finally, we review Japanese health economics studies to determine the level of PSA use in Japan. Guidelines published before 2008 recommend conducting a sensitivity analysis, but do not specify a method. In contrast, both the French, American and English guidelines, which were published after 2011, specifically recommend using a PSA. In Japan, the “Guideline for economic evaluation of healthcare technologies in Japan” recommends conducting a PSA, “if possible”. However, PSA methods are not widely used in Japan. Of 49 Japanese health economics studies based on quality-adjusted life years, only six conducted a PSA (12.2%), although 35 (71.4%) did conduct other types of sensitivity analyses. If PSA methods are accepted as a good way to determine the robustness of an evaluation, then we need to foster their use. This, in turn, means we need specific guidelines on how best to use these methods.

We studied the efficacy of the combined formulation of Ku-Oketsu-zai and Sei-Netsu-zai for the erythrofacia-type eruption the atopic dermatitis patients.
Among twenty patients with erythrofacia type eruption of the atopic dermatitis, fifteen patients (75%) showed Oketsu condition and five patients (25%) did not showed. In seven patients showing Oketsu condition with constipation (46.7%), the combined formulation of Sei-Netsu-zai and To-kaku-jyoki-to was effective significantly, In eight patients showing oketsu condition without constipation (53.3%), the combined formulation of Sei-Netsu-zai and To-kaku-jyoki-to was also effective.
We should consider to use the combined formulation of Sei-Netsu-zai and To-kaku-jyoki-to for the treatment of the erythrofacia-type eruption of the atopic dermatitis.

A 43-year-old woman underwent aortic valve replacement for aortic regurgitation causing aortitis syndrome. The postoperative course had been uneventful and inflammation was controlled by steroid therapy. She developed a moderate degree of dyspnea with cardiomegaly. Two years after the first aorta valve replacement (AVR), severe aortic regurgitation was observed on both echocardiography and aortography. Dehiscence of the prosthetic valve was suspected and an emergency operation was performed. To secure the reimplanted prosthetic valve, we applied the technique of passing felt-pledgeted sutures through the aortic wall in the vicinity to the right coronary cusp and the noncoronary cusp and others through the left coronary cusp with everting mattress sutures. The postoperative course of the second AVR has been uneventful for two months. Since prosthetic valve detachment can occur even if inflammation of aortitis is well controlled, strict management of inflammation is recommended for a prolonged period to prevent reccurence of aortitis and subsequent valve dehiscence.