An evaluation of tuberculosis skin test screening program in British Columbia long-term care facilities

Tuberculosis has been considered an occupational risk for health care workers since the 1930s. Over the past six decades, however, TB incidence and TB infection rates have dramatically decreased. This decline has been largely due to improved living conditions, nutrition and pharmaceutical treatment. Today, opinions about TB risk in the health care settings vary considerably and include the view that health workers are at no increased risk for TB infection compared to the general population. TB screening programs have been operating in British Columbia long-term care facilities (LTCFs) since 1987. The primary interest of these programs has been to monitor the risk that employees of these health care facilities have. The purpose of this thesis is to evaluate these screening programs based on the following questions: 1. Is the TB incidence of LTCF employees higher than that of the general population who are similar in age, gender and ethnic origins? 2. Is TB infection rate of LTCF employees higher than that found in similar studies in other jurisdictions? 3. What are the costs of the screening program and how do these costs compare with the costs of treating active TB cases that would have occurred if the screening program had not been in place? Analyses of the B. C. TB Control five year data has revealed that TB incidence of L TCF employees is not greater than the general population when age, gender and ethnic origin are controlled. An analysis of TB incidence rate by each ethnic group (immigrants, First Nations and other Canadians), revealed that the TB incidence rate in immigrants and First Nations are 6 and 53 times, respectively, higher than Canadian born. Further, the TB incidence in each ethnic group is consistent with its corresponding population. These results suggest that TB is more related to birthplace than to working place. The TB infection rate (21.9%) in British Columbia long-term care facility employees found in this study is in the mid-range of studies in other jurisdictions. When analysis was performed in each ethnic group, it was found that the infection rate in immigrants (52.3%, 95% CI is 3.23-3 .58) and First Nations (46.3%, 95% CI is 2.49-3 .61) are much higher than Canadian born (10.6%). However, the TB infection rate in adult care facility employees (24.6%) is not greater (95% CI is 0.87-1.0) than that of child care facility employees (17. 6%) after adjusting for age, gender and ethnic origin. TB infection rate is also more related to birthplace than to the working place. INH preventive therapy is provided to those who are found to be PPD positive to prevent the occurrence of active TB from TB infection. It was calculated that the cost of preventing of one TB case ($58,272) is much higher than the treatment of active TB ($10,304). From this perspective, this program should be stopped. However, considering the high TB infection rate in immigrants and First Nations, the TB screening program should target to these high risk groups to prevent the potential reactivation of TB.