Sensitivity and specificity of an electronic nose in diagnosing pulmonary tuberculosis among patients with suspected tuberculosis

• Published in: PloS one Vol. 14; no. 6; p. e0217963
• Main Authors: Saktiawati, Antonia M I, Stienstra, Ymkje, Subronto, Yanri W, Rintiswati, Ning, Sumardi, Gerritsen, Jan-Willem, Oord, Henny, Akkerman, Onno W, van der Werf, Tjip S
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13-06-2019; Public Library of Science (PLoS)
• Subjects: Adolescent; Adult; Aged; Alcoholic beverages; Antibiotics; Asthma; Biology and Life Sciences; Body mass; Body mass index; Body size; Breath tests; Breath Tests - instrumentation; Calibration; Case-Control Studies; Chronic obstructive pulmonary disease; Diagnosis; Diagnostic imaging; Direct reduction; Electronic Nose; Electronic noses; Equipment and supplies; Female; Food intake; Health care; Health facilities; HIV; Human immunodeficiency virus; Humans; Indonesia - epidemiology; Infectious diseases; Influenza; Internal medicine; Lung cancer; Male; Medical diagnosis; Medicine; Medicine and Health Sciences; Methods; Microscopy; Middle Aged; Nose; Nursing; Patients; Pattern recognition systems; Physical Sciences; Physiological aspects; Point-of-Care Systems; Public health; Pulmonary tuberculosis; Radiography; ROC Curve; Rural areas; Sensitivity; Sensitivity analysis; Sensitivity and Specificity; Sensors; Signs and symptoms; Smear; Smoking; Sputum; Statistical analysis; Studies; Tuberculosis; Tuberculosis, Pulmonary - diagnosis; Tuberculosis, Pulmonary - epidemiology; VOCs; Volatile organic compounds; Young Adult; Indonesia; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0217963

To investigate the potency of a hand-held point-of-care electronic-nose to diagnose pulmonary tuberculosis (PTB) among those suspected of PTB.
Setting: Lung clinics and Dr. Sardjito Hospital, Yogyakarta, Indonesia. Participants: patients with suspected PTB and healthy controls. Sampling: 5 minutes exhaled breath. Sputum-smear-microscopy, culture, chest-radiography, and follow-up for 1.5-2.5 years, were used to classify patients with suspected PTB as active PTB, probably active PTB, probably no PTB, and no PTB. After building a breath model based on active PTB, no PTB, and healthy controls (Calibration phase), we validated the model in all patients with suspected PTB (Validation phase). In each variable (sex, age, Body Mass Index, co-morbidities, smoking status, consumption of alcohol, use of antibiotics, flu symptoms, stress, food and drink intake), one stratum's Receiver Operating Characteristic (ROC)-curve indicating sensitivity and specificity of the breath test was compared with another stratum's ROC-curve. Differences between Area-under-the-Curve between strata (p<0.05) indicated an association between the variable and sensitivity-specificity of the breath test. Statistical analysis was performed using STATA/SE 15.
Of 400 enrolled participants, 73 were excluded due to extra-pulmonary TB, incomplete data, previous TB, and cancer. Calibration phase involved 182 subjects, and the result was validated in 287 subjects. Sensitivity was 85% (95%CI: 75-92%) and 78% (95%CI: 70-85%), specificity was 55% (95%CI: 44-65%) and 42% (95%CI: 34-50%), in calibration and validation phases, respectively. Test sensitivity and specificity were lower in men.
The electronic-nose showed modest sensitivity and low specificity among patients with suspected PTB. To improve the sensitivity, a larger calibration group needs to be involved. With its portable form, it could be used for TB screening in remote rural areas and health care settings.