Diagnostic Tools Used for Tuberculous Pleural Effusion and Their Association With Treatment Outcomes

Background Tuberculous pleural effusion (TPE) is difficult to confirm because pleural disease is often paucibacillary. Pleural-fluid biomarkers, culture, molecular assays, and pleural biopsy can improve diagnostic certainty, but their availability varies substantially in resource-limited settings. Objective To describe the diagnostic investigations used for suspected TPE at AlShaab and Abu Anjaa Teaching Hospitals in Khartoum, Sudan, from February to July 2017, and assess their association with treatment outcomes. Methodology This retrospective cohort study included 69 patients with a clinician-recorded diagnosis of TPE at two teaching hospitals in Khartoum, Sudan, from February to July 2017. The first author collected demographic, clinical, investigation, treatment, and outcome data from patient records using a standardized data-collection checklist. Investigations were classified according to whether a test and result were documented. Associations with outcome were assessed using Fisher's exact test and odds ratios (ORs) with 95% confidence intervals (CIs). Results Chest radiography was performed in 67/69 patients (97.1%). Pleural-fluid adenosine deaminase (ADA) was recorded in 1/69 (1.4%), culture in 6/69 (8.7%), polymerase chain reaction (PCR) in 4/69 (5.8%), and pleural biopsy in 7/69 (10.1%). GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA) and pleural-fluid interferon-gamma testing were not performed. HIV testing was not documented in 50/69 patients (72.5%). Thirteen patients (18.8%) received antituberculous treatment without pleural-fluid or tissue testing. Five (38.5%) had a favorable outcome, and eight (61.5%) had an unfavorable outcome, including four subsequently diagnosed with malignant effusion and one death. Among 56 patients who underwent at least one pleural-fluid or tissue test, 39 (69.6%) had a favorable outcome. Any diagnostic testing was associated with higher odds of favorable outcome (OR 3.67, 95% CI 1.05-12.87; Fisher's exact P = 0.054), although the association did not cross the conventional statistical-significance threshold. Conclusions Confirmatory testing for suspected TPE was used inconsistently, while several clinically useful tests were rarely or never available. Patients treated without pleural-fluid or tissue testing had more unfavorable outcomes, including missed malignant effusion. The findings support a pragmatic minimum diagnostic bundle before prolonged empiric treatment, while recognizing that this observational study cannot establish that testing caused better outcomes.