Seasonal variation and hospital utilization for tuberculosis in Russia: hospitals as social care institutions.

BACKGROUND: Clinical management of tuberculosis in Russia involves lengthy hospitalizations, in contrast to the recommended strategy advocated by the World Health Organization. METHODS: We used Fourier transform, spectral analysis and Student's t-test to analyse periodic and seasonal variations in admission and discharge rates for tuberculosis hospitalizations in 1999-2002, using routinely captured data from the Samara Region, Russia. RESULTS: Hospital admissions in colder months were significantly higher than in warmer months. The mean monthly adjusted number of admissions in colder and warmer months for all adults was 413 and 372 (P < 0.01), for unemployed adults 218 and 198 (P < 0.02) and for pensioners 104 and 82 (P < 0.05). Hospital discharges varied seasonally. Maximum differences between admissions and discharges occurred in colder months and minimum differences were observed in warmer months. CONCLUSIONS: As hospitalizations of tuberculosis patients in colder months fulfil an important social need, shifts to ambulatory care must be carefully managed.