The aim of this research was to determine the treatment results for TB patients in the province of Kermanshah over the years 2005-2017. Tuberculosis as an infectious disease known as calamity to the human community for a long time. According to the World Health Organization (WHO) reports, the average yearly incidence of tuberculosis in the world is 151 per 100,000 individuals and 16.31 in Iran(2, 11).There were also a 13.95 per 100,000 individuals yearly rate of tuberculosis in the province of Kermanshah.
In the 13-year study period, the highest incidence of disease was above 60 years, which may be attributed to a weakened immune system at an older age or to the consequences of tobacco consumption and air pollution, which are not discussed in this research. It requires more consideration in terms of improving health and enhancing the prevention of TB in the aging lifestyle. These research results are consistent with reports from other studies on the high incidence of tuberculosis among aging people(1, 12).
Treatment success rates for TB patients were 85.9% in 2005-2017 (improved+ completion of treatment), Which is higher than the 2016 WHO report (82%)(2), suggesting the DOTS ' promising performance in tuberculosis prevention in Iran. The high success level for tuberculosis treatment was attributed to many factors; the most significant is the use of experienced human forces and the regular follow-up of individuals taking the drug. But there are also obstacles to 100% effective tuberculosis treatment, some of the most important causes of failure in tuberculosis treatment are the community's negative attitude towards TB patients, lack of knowledge about the disease and its transmission to others, lack of awareness of free diagnostic and treatment services at all levels of health care, lack of anti-tuberculosis therapy, problems regarding admission to treatment centers and insufficient services by health care staffs, indicated that removing these barriers could increase treatment success rates.
Of those suffering from tuberculosis, 67.2% had pulmonary tuberculosis and 32.2% had extrapulmonary tuberculosis. There has been no significant change in the incidence rate in Iran over the past 13 years. Overall, nearly three-quarters of patients were afflicted by pulmonary TB based on the findings of this report and similar studies, and one-quarter had extrapulmonary TB(1). The high percentage of pulmonary TB disease compared with extrapulmonary tuberculosis was attributable to the probability of pulmonary TB transmission and the inability to transmit pulmonary TB to other individuals. 74.8% of patients lived in urban areas and 25.2% in rural areas. City patients were more likely to fail treatment than rural patients; Which is consistent with similar studies in this field (13, 14). Many individuals with TB generally live in urban areas. The high prevalence of urban patients in rural areas was due to the high proportion of patients in urban environments as well as the high density of population in urban areas than in rural areas. Iran's high rate of development in rural areas owing to the establishment of health houses in rural areas as well as the effective care provided by experienced health professionals and disease treatment process leading to better treatment in rural areas than urban areas.
More than 50% of patients in Western Iran are males, which is roughly equal to the proportion of the population which indicates that men and women have the same chance of developing TB, but still, according to the World Health Organization, the rate of men at 64% is higher than women at 36% (2) While infection rates are the same for both genders, the proportion of male deaths is higher than for females, which is consistent with studies in this field(15). One possible reason for men's elevated attenuation level is the lack of timely treatment or professional instructions.
When age rose, the likelihood of completing treatment decreased, with those over60 experiencing lower chances of completing treatment and higher mortality than those below 18 years of age. Furthermore, as age increases due to lower rates of immunity, the probability of death in these patients grows. The odds of treatment failure in the 19-29 age group are lower than in the "under 18" age group. The treatment failure may have been due to the lack of consistent adolescent follow-up after complete recovery. The most regular patient(13). was the age group of 40-31 years in the northwestern Iranian sample. In another report on the 10-year trend of tuberculosis in West Azerbaijan province, the most commonly reported illness was reported to the group aged 65-31 years(16).
The chances of treatment failure for TB disease have decreased by growing the body mass index (BMI) at univariate level but there was no statistically significant relationship between BMI and treatment outcomes after controlling for other confounding factors. However, lower BMI owing to immunodeficiency, according to some reports, has dramatically increased the chance of death in patients with tuberculosis(17, 18).
The prevalence of HIV-positive patients in this research was 31.0% (excluding patients of unknown HIV status), 12.3% of whom were rural and 36.3% urban. The prevalence of HIV-positive TB cases was 13.7%, 6.3% rural and 7.3% urban(19) in a Chinese survey. For HIV-positive cases, the chances of death are lower than in patients with HIV-free TB, which was consistent with previous findings(20-22).
In the present study, 38.9 percent of patients have been admitted to the hospital, Patients hospitalized longer were also more likely to die as a result of severe illness, severe drug side effects, drug-resistant TB patients, and HIV-infected TB patients. The mortality rate for hospitalized patients was 14.5%, which is consistent with Saudi Arabia study findings (14%) (23). It is also slightly higher than the mortality rate recorded by Taiwan (12.3%) and less than that found by China (18.9%) (24, 25).
Study weaknesses and strengths
One of this study's main strengths is the large sample size and being long-term population-based research. Other strengths of this analysis are correctly evaluating and complete treatment outcomes and collecting information from field experts. The lack of evaluation of the effect of diabetes and smoking on the treatment results of TB patients was one of the drawbacks of this research.