Factors related to early case detection of tuberculosis in health service facilities for the elderly

Abstract

The proportion of newly notified tuberculosis cases aged over 65 years has been rising and reached 49.2% in 2001. For this reason, the Ministry of Health, Labor and Welfare recommended in 1999 to give preventive therapy for tuberculosis to elderly persons with fibrous lesions on chest X-ray. However, our research pointed out many problems in the matter and low public health benefits of preventive therapy. At present, early case detection and treatment are considered to be the most effective tuberculosis control measures for the elderly in Japan. For the purpose of developing the most effective case finding method for the elderly, we investigated various aspects of tuberculosis in health service facilities for the elderly. Health service facilities for the elderly were established since 1988 to provide nursing care and rehabilitation services to enable elderly persons who no longer need hospitalized care to return home. Questionnaires were mailed to 358 health service facilities for the elderly in a metropolitan city and 4 prefectures. One hundred and sixty-nine facilities (47.2%) responded. Among them, 61 (36.1%) are attached to hospitals, 21 (12.4%) are attached to clinics, and 87 (51.5%) are not attached to any medical facilities. The median duration from the opening of the facility was 3.5 years, and 113 (66.9%) facilities were founded within 5 years. The mean age was 83.2 years for facility-care users and 79.6 years for day-care users. The mean duration of care was 7 months for facility-care users and 13 months for day-care users. Pre-admission chest X-ray was conducted for facility-care users in 72 (42.6%) facilities, and for day-care users in 40 (23.7%) facilities. Comparing with 84.3% (Shishido, 2002) in special nursing homes for the elderly, the rate was significantly lower in health service facilities for the elderly. Periodic TB screening during care utilization was also less frequently carried out in health service facilities for the elderly (45.6% for facility-care users and 15.4% day-care users). A possible reason is that special nursing homes for the elderly are mandated to conduct periodic TB screening as provided by the TB Control Law, while health service facilities for the elderly are not under such provision. Periodic TB screening for employees was carried out in 160 (94.7%) facilities. Respiratory symptoms were less frequently checked compared with anorexia or lassitude. Thirty-two facilities (18.9%) checked the facility-care user everyday for respiratory symptoms using a check-list, while 114 facilities (67.5%) checked only for anorexia or lassitude (p < 0.01). When persistent respiratory symptoms were observed in facility-care users, 157 (93.5%) facilities referred them to hospitals with letters explaining their symptoms and 108 (63.9%) facilities requested chest X-ray and sputum tests. However, for day-care users, most facilities only advised them to visit medical institution without any letter of referral. Within 5 years, 52 (30.8%) facilities reported 65 TB cases among facility users and 5 (3.0%) facilities reported 5 TB cases among employees. Based on person-year, case rate was calculated to be 104.6 per 100,000 among elderly facility users. This rate was compared with that of people aged 75 years over in the community. Rate ratio was 1.04 (95% CI: 0.82-1.34). The risk of developing tuberculosis was slightly higher in the elderly facility users, but the risk was not statistically significant. This result may be influenced by the low response rate from facilities with tuberculosis cases. We conclude that it is very important to detect TB cases at the early stage of disease not only to protect the elderly from tuberculosis death but also to prevent outbreak of tuberculosis infection in health service facilities for the elderly. Effective and feasible tuberculosis control for the elderly should be provided under the TB control Law and be implemented with the cooperation from related medical institutions and public health centers.