TB Type and Spirometry Result vs. Functional Capacity Based on 6MWT in People With Post-TB Lung Disease

Tuberculosis (TB) remains a major global health problem, ranking second after COVID-19 among infectious agents causing mortality worldwide. Post-Tuberculosis Lung Disease (PTLD) is defined as chronic respiratory impairment following pulmonary TB, with manifestations that affect both large and small airways, reduce life expectancy, increase the risk of TB recurrence, and occur with a prevalence ranging from 18% to 87%. Adolescents recovering from pulmonary TB often experience persistent respiratory symptoms, reduced lung volumes, and impaired exercise capacity, leading to long-term health consequences such as cough, fatigue, shortness of breath, and limitations in daily activities.

This study aims to analyze the correlation between type of tuberculosis, spirometry results, and functional capacity in adolescents with PTLD. An analytical observational design with a cross-sectional approach will be employed. The study will be conducted at Hasan Sadikin General Hospital, Bandung, Indonesia, from March to May 2026. Eligible participants are adolescents aged 10-18 years, diagnosed with PTLD by a pediatrician, and capable of performing the 6-Minute Walk Test (6MWT). Exclusion criteria include other lung diseases or physical limitations preventing completion of the 6MWT.

Spirometry will be performed according to American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines. Participants will complete a forced vital capacity (FVC) maneuver consisting of full inspiration to total lung capacity, followed by a rapid, forceful, and sustained expiration into the mouthpiece for at least 6 seconds (or until a volume plateau is achieved). A subsequent rapid inspiration will be performed to complete the flow-volume loop when required. A minimum of three acceptable maneuvers will be obtained for each participant to ensure reproducibility. Forced Expiratory Volume in 1 second (FEV1) and Forced Vital Capacity (FVC) will be recorded in liters at each assessment time point.

Functional capacity will be assessed using the standardized 6MWT, conducted along a marked corridor. Participants will be instructed to walk back and forth for six minutes, and the total distance covered will be recorded in meters. Metabolic equivalents (METs) will be estimated from walking speed using the ACSM walking equation: VO₂ (ml/kg/min) = 3.5 + 0.1 × speed (m/min), with METs calculated as VO₂/3.5. Both spirometry and 6MWT outcomes will be summarized using descriptive statistics, and correlations between variables will be analyzed using Pearson or Spearman correlation tests, followed by linear regression where appropriate. A significance level of p < 0.05 will be applied.

Ethical approval will be obtained from the institutional ethics committee, and informed consent will be secured from participants and/or guardians. Confidentiality of respondent data will be strictly maintained. The findings are expected to enhance understanding of post-TB recovery, inform specific rehabilitation strategies, and contribute to health interventions for adolescents with PTLD.

Inclusion criteria

• Adolescents (10-18 year old)
• Diagnosed with post tuberculosis lung disease by pediatrician
• Capable of performing the 6MWT

Exclusion criteria

• Diagnosed with another lung disease
• Having physical limitations that hinder the 6MWT