Tuberculosis treatment outcome in elderly patients: a retrospective monocentric observational study

The incidence of tuberculosis (TB) in developed countries is decreasing. Among natives, the highest occurrence is in >65 years old (y.o.) patients (pts). Data on tolerance of first-line regimens and treatment success rate (TSR) for elderly pts are limited. We decided to investigate whether > 65y.o. pts had higher risk of drug intolerance resulting in treatment failure compared to younger pts. We conducted a retrospective study of 6390 consecutive adult pts treated for TB with a first-line regimen at our referral center from 2000 to 2022. Our population's TSR was 91.1% (5823 pts). Among pts >65 y.o., the TSR was 88.8%, compared to 91.5% in the younger population (p=0.006). For older pts, modifications to the standard regimen due to drug intolerance were necessary in 5.4% vs 3.3% in pts <65 y.o. (p<0.003). Permanent discontinuation was reported in 1% vs 0.2% (p<0.001). Another significant cause of treatment failure in the elderly was death (6.2% vs 0.3%, p<0.001). Conversely, treatment failure in pts <65 y.o. was mainly attributed to spontaneous interruptions and relocation to other centers/countries (7.9% vs 4.1%, p<0.001). Older patients often face a higher risk of adverse drug effects due to a greater incidence of comorbidities and concomitant medications, leading to significantly more common modifications of the standard regimen in our population. In our study, despite the significant difference between the age groups, the TSR in the elderly remained above the global TSR reported by the World Health Organization in 2021. We believe that early identification of signs of drug intolerance and prompt modification of the standard regimen is fundamental to enscure treatment success.