Frequency of hospitalisations and inpatient care costs of manic episodes: in patients with bipolar I disorder in France.

Background: Bipolar disorder is a chronic illness that may involve multiple relapses and result in substantial psychosocial impairment. However, very few recent studies have investigated the economic burden of the disease.

Objective: To assess the frequency of hospitalisation and the inpatient care costs associated with manic episodes in patients with bipolar I disorder in France.

Method: A cost-of-illness study was conducted based on available data using a hospital payer perspective. The lifetime prevalence of manic episodes was estimated from published epidemiological data using a random-effects meta-analysis. Data were obtained by a computerised literature search using the main scientific and medical databases. Additional epidemiological references were identified from published studies and textbooks. Data on frequency of hospitalisation and length of stay were collected from a large psychiatric university hospital. Data on unit costs for inpatient care were obtained from the accounting system of the largest hospital group in Paris, France for the year 1999.

Results: Extrapolating from international data on the average prevalence of bipolar I disorder, the proportion of rapid cycling patients and the average cycle duration, we estimated the annual number of manic episodes in patients with bipolar I disorder to be around 265,000 in France. Based on hospital data in Paris, the proportion of manic episodes that require hospitalisation was estimated to be around 63%. The average length of stay was 32.4 days and the hospitalisation-related costs were estimated to be around 8.8 billion French francs (Euro 3 billion) [1999 values].

Conclusion: Our study highlights the lack of medical and economic data on the frequency and hospitalisation-related costs of manic episodes in patients with bipolar I disorder in France. As the lifetime prevalence of bipolar I disorder may be as high as 3% among adults, further studies are required in order to provide representative national data and to allow economic evaluations of costs related to bipolar I disorder in France.