HEALTH-RELATED QUALITY OF LIFE, COMORBIDITIES AND MORTALITY IN NONTUBERCULOUS MYCOBACTERIAL INFECTIONS: A SYSTEMATIC REVIEW

Purpose:

   To systematically review the health-related quality of life (HRQOL), comorbidities and mortality associated with nontuberculous mycobacterial (NTM) disease, an emerging clinical and public health concern. Given the increased susceptibility of an aging population, the prevalence of NTM infections and mortality have increased worldwide over the last decades.

 

Method:

   We searched MEDLINE, EMBASE, CINAHL, Scopus Life Sciences, conference proceedings and Google from the earliest date available to February 2015 for primary studies in high-income jurisdictions. Search terms related to NTM, patient preferences, sequelae, prognosis and survival were developed in consultation with a librarian. We snowball searched reference lists. Eligible studies compared populations with and without NTM disease, excluding studies that examined HIV populations exclusively. Two reviewers independently screened articles, extracted data and appraised study quality using the STROBE checklist. We followed MOOSE and PRISMA reporting guidelines. All languages were accepted. Findings were summarized qualitatively. 

Result:

   Of 3,193 citations screened, 19 studies were included, spanning nine countries with the majority from Taiwan (n=8) followed by the United States (n=4). One assessed HRQOL, one assessed comorbidities, 14 assessed mortality and three assessed multiple outcomes. NTM populations reported significantly worse HRQOL than non-NTM populations when measured on the visual analogue scale, but not when derived from time trade-off. Two of four comorbidity studies suggested NTM populations experienced more Aspergillus spp.-related diseases. Two suggested greater risk of bronchiectasis and one suggested greater risk of pulmonary tuberculosis. Mortality results were conflicting. Most (n=9) suggested no difference between comparators, although four studies—two of which were deemed of high quality, suggested NTM populations fared worse. One lower quality study suggested NTM populations fared better. High clinical heterogeneity in study design and study quality may explain discordant results. Overall, assessments of biases and reporting were done poorly: only one study measured potential misclassification of NTM and two of 16 cohort studies reported patient attrition over follow-up. 

Conclusion:

   While no strong consensus emerged on how populations with NTM compared to those without NTM, the 19 studies suggest an increased health burden from a range of respiratory diseases, as well as a potentially increased mortality associated with NTM disease. More high quality studies are needed to address biases in order to support clinical care and to inform healthcare planning.