Disturbance of functionality is one of the core features of schizophrenia, and has deleterious effects on a patient’s employment, increased healthcare costs, and a large societal burden. Thus, if a patient’s disability status could be predicted, and interventions needed identified in advance, poor outcomes could be prevented. To achieve this aim, we developed a method by which to assess dynamic changes of dysfunction and estimate the lifetime duration of disability in patients with schizophrenia, as a proxy for assessing their specialized healthcare needs.

The proposed method was developed based on a nationwide database and a cross-sectional survey. The primary analysis investigated the dynamic change in the proportion of patients with manifested disability over time, while the secondary analysis estimated the lifetime duration of disability, obtained as the proportion of patients with manifested disability multiplied by the survival probability throughout the life of patients.

The average lifetime duration of manifested disability of global functioning was estimated to be 20.9 years, which represents approximately 73% of the whole lifetime of patients. The duration of disability in socially-useful activities was estimated to be 15.6 years, while that in personal and social relationships was 17.5 years. The female patients had a longer duration of manifested disability (22.9 years) than the male patients (19.5 years).

The developed method of analysis indicated that the longest lifetime durations of manifest disability were observed in the areas of socially-useful activities and personal and social relationships, and the proportions of patients with these disabilities rapidly increased at 200 months after diagnosis.