Risk factors affecting treatment outcomes for pulmonary tuberculosis in Finland 2007–2014: a national cohort study

Abstract

Background: Major transition in tuberculosis (TB) epidemiology is taking place in many European countries including Finland. Monitoring treatment outcome of TB cases is important for identifying gaps in the national TB control program, in order to strengthen the system. The aim of the study was to identify potential risk factors for non-successful TB treatment outcomes, with a particular focus on the impact of comorbidities. We also evaluated the treatment outcome monitoring system. Methods: All notified microbiologically confirmed pulmonary TB cases in Finland in 2007-2014 were included, except multi-drug resistant (MDR) cases. Nationwide register data were retrieved from: Infectious Diseases Register, Population Register, Cause of Death Register and Hospital Discharge Register. Non-successful outcomes were divided into three groups: death, unsatisfactory outcomes and non-defined outcomes. Logistic regression analyses were used to identify risk factors for non-successful outcomes. Results: Treatment outcomes were notified for 98.6% of study cases (n = 1396/1416). Treatment success rate was 75%. The main reason for non-successful outcome was death (16%), whereas outcomes failed and lost to follow-up were rare (1% together). In a multivariable model, risk factors for death as outcome were increasing age, male gender and Charlson comorbidity index ≥1, for unsatisfactory outcomes non-MDR drug resistance and TB registered in the first study period, and for non-defined outcomes non-MDR drug resistance. Among 50 cases with unsatisfactory outcomes, we observed false outcome allocations in eight (16%), and > 2% of the cases transferred to another country or disappeared before or during treatment. Conclusions: With a high proportion of older population among tuberculosis cases, death is a common treatment outcome in Finland. Comorbidity is an important factor to be incorporated when interpreting and comparing outcome rates. There was a considerable inconsistency in outcome allocation in the monitoring system, which implies that there is need to review the guidelines and provide further training for outcome assessment.

Multidrug-resistant tuberculosis in Finland: treatment outcome and the role of whole-genome sequencing

“…We need to improve our treatment programme as for almost one-fifth of our cases MDR-TB treatment was interrupted or the patient transferred to another country during treatment resulting in high risk of treatment interruption. On the other hand, our treatment success rate of 71% among pulmonary MDR-TB cases is close to the rate published earlier for pulmonary non-MDR-TB cases in Finland [ 26 ]. Nevertheless, direct conclusions about MDR versus non-MDR cases cannot be made as demographics among these two cohorts differ substantially; MDR cases are much younger, have less comorbidities and are more often of foreign origin [ 26 ].…”

“…On the other hand, our treatment success rate of 71% among pulmonary MDR-TB cases is close to the rate published earlier for pulmonary non-MDR-TB cases in Finland [ 26 ]. Nevertheless, direct conclusions about MDR versus non-MDR cases cannot be made as demographics among these two cohorts differ substantially; MDR cases are much younger, have less comorbidities and are more often of foreign origin [ 26 ].…”

Factors associated with mortality among patients with culture-positive pulmonary tuberculosis in the urban poor population of Osaka City, Japan

“…Similar findings were reported in Australia, ( 6 ) Denmark, ( 12 ) China, Taiwan (China), ( 16 ) Spain, ( 17 ) the Republic of Korea, ( 18 ) the United Kingdom ( 19 ) and Finland. ( 20 ) We also found that a higher proportion of early deaths were TB-specific rather than non-TB-specific, which suggests that patients who survive > 2 months of TB treatment have better outcomes, and late deaths are due more commonly to causes other than TB.…”

“…Advanced age is well recognized as a risk factor for morbidity and mortality from TB because of weakening of both the innate and adaptive immune systems. ( 21 ) The presence of comorbidity has also been identified as the most common characteristic of death from TB in other developed countries, such as Australia, ( 6 ) Denmark, ( 12 ) Finland, ( 20 ) the Netherlands, ( 22 ) Spain, ( 17 ) Singapore, ( 23 ) the Republic of Korea, ( 18 ) China, Taiwan (China) ( 9 , 11 , 24 ) and the USA. ( 10 ) Older people tend to be more vulnerable to comorbidity, as suggested by a one-day survey of the prevalence of morbidity in 2017 conducted by random stratified sampling in 6402 hospitals (76% of hospitals in Japan), which showed that the rate of comorbidity among people aged ( 2 )65 years was 17 times higher than among those aged 20–24 years.…”

Treatment outcomes and influencing factors on patients with Pulmonary Tuberculosis: a retrospective study

“…Elder age, type of tuberculosis disease, prior tuberculosis cure, very low income, incomplete contact to transport, distance from treatment center to the home, low information about the disease and its dealing, partial public funding, multidrug high resistance, and comorbidity specially with HIV have all been investigated to be associated with ineffective treatment consequences [7][8][9][10][11][12]. The ultimate goal of the strategy to end the global TB epidemic by 2035 is to reduce TB-related deaths by 95% and the prevalence rate of TB by 90% [13,14]. Understanding the factors related to the outcomes of TB treatment is critical.…”