In Japan, almost everyone is covered by national health insurance and pay 30 percent of medical fee. Patients generally have the freedom to choose the health care provider that they feel best fits their needs without concerns regarding costs.
The survey was conducted of a single family practice. The physician had 22 years of clinical experience and had been well-trained in the diagnosis and treatment of depression. The clinic was a solo practice under private management, located in Matsudo City, a suburb of Tokyo, Japan. The number of patients seen daily in the clinic generally ranged between 80 and 110 (average number 95). Approximately 10 percent of the patients seen were there for their first visit, and 45 percent of the patients were adults. Research clinics were pre-arranged, so that a research nurse was available to perform structured interviews. Research clinics were set for every second and fourth Saturday from April to September 2004, every second Saturday from November 2004 to March 2005, and every second Tuesday and Saturday from September 2005 to August 2006. The survey was conducted over a total of 25 days within the study period.
All consecutive new adult patients attending the above-noted research clinics for the first time were enrolled in the study. To be eligible, a patient had to be 18 or more years old and had to provide informed consent. Patients were excluded if they had a high fever (≥ 38.0°C), or any condition requiring emergency management, such as impaired consciousness, extensive drug reactions or deep burns. Otherwise eligible subjects also were excluded if they were unable to complete the questionnaire for any reason (e.g., patients with language barriers, dementia or visual disturbance).
The survey was conducted in the following order. First, each new adult patient was asked to complete a written questionnaire in the waiting room. This questionnaire included questions on socio-demographics, in addition to the following question: "What is your problem? Please write the reason for your visit." Second, the Japanese version of the Mini-International Neuropsychiatric Interview (J-MINI) was conducted by a research nurse in the interview room. Third, the doctor performed his usual clinical practice and recorded his own clinical diagnosis on the face sheet of each patient's registration form. Note that the research interview conducted by the research nurse and the clinical evaluation performed by the physician were carried out independently. Finally, the reason for visit and the clinical diagnosis were classified according to the International Classifications for Primary Care, Second Edition (ICPC-2) by an investigator independent of the attending physician and research nurse. The degree of agreement between the results of the research interview and the clinical evaluation were estimated, in terms of the diagnoses of Major Depressive Episode and Alcoholism, using kappa statistics, calculated using SPSS, version 11.0J.
The MINI is an abbreviated, structured, diagnostic interview that requires an administration time of 10–20 minutes. It is designed to allow non-specialists who have received formal training to screen for certain psychiatric diagnoses. It conforms both to the International Classification of Mental and Behavioral Disorders, Tenth Revision (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), and has been validated relative to the Structured Clinical Interview for DSM-III-R (SCID) and the Composite International Diagnostic Interview (CIDI) . The Japanese version of the MINI (J-MINI) also has been validated . Prior to starting this survey, research nurses received practical training in the use of an instruction videotape, dealing with the use of the MINI, a training process which was comparable to the standard training packet used in the study validating the J-MINI.
The ICPC-2 is problem-oriented disease classification system developed by the World Organization of Family Doctors (WONCA). It has compatibility with the ICD-10, and health care providers can classify, using a single classification, three important elements of the health care encounter: the reasons for the encounter, the diagnoses or problems, and the process of care .