Diagnostic accuracy of an integrated respiratory guideline in identifying patients with respiratory symptoms requiring screening for pulmonary tuberculosis: a cross-sectional study.

BACKGROUND: To evaluate the diagnostic accuracy of the integrated Practical Approach to Lung Health in South Africa (PALSA) guideline in identifying patients requiring bacteriological screening for tuberculosis (TB), and to determine which clinical features best predict suspected and bacteriologically-confirmed tuberculosis among patients with respiratory symptoms. METHODS: A prospective, cross-sectional study in which 1392 adult patients with cough and/or difficult breathing, attending a primary care facility in Cape Town, South Africa, were evaluated by a nurse using the guideline. The accuracy of a nurse using the guideline to identify TB suspects was compared to that of primary care physicians' diagnoses of (1) suspected TB, and (2) proven TB supported by clinical information and chest radiographs. RESULTS: The nurse using the guideline identified 516 patients as TB suspects compared with 365 by the primary care physicians, representing a sensitivity of 76% (95% confidence interval (CI) 71%-79%), specificity of 77% (95% CI 74%-79%), positive predictive value of 53% (95% CI 49%-58%), negative predictive value of 90% (95% CI 88%-92%), and area under the receiver operating characteristic curve (ARUC) of 0.76 (95% CI 0.74-0.79). Sputum results were obtained in 320 of the 365 primary care physicians TB suspects (88%); 40 (13%) of these were positive for TB. Only 4 cases were not identified by the nurse using the guideline. The primary care physicians diagnostic accuracy in diagnosing bacteriologically-confirmed TB (n = 320) was as follows: sensitivity 90% (95% CI 76%-97%), specificity 65% (95% CI 63%-68%), negative predictive value 7% (95% CI 5%-10%), positive predictive value 99.5% (95% CI 98.8%-99.8%), and ARUC 0.78 (95% CI 0.73-0.82). Weight loss, pleuritic pain, and night sweats were independently associated with the diagnosis of bacteriologically-confirmed tuberculosis (positive likelihood ratio if all three present = 16.7, 95% CI 5.9-29.4). CONCLUSION: The PALSA guideline is an effective screening tool for identifying patients requiring bacteriological screening for pulmonary tuberculosis in this primary care setting. This supports the randomized trial finding that use of the guideline increased TB case detection.

Effect of educational outreach to nurses on tuberculosis case detection and primary care of respiratory illness: pragmatic cluster randomised controlled trial.

OBJECTIVES: To develop and implement an educational outreach programme for the integrated case management of priority respiratory diseases (practical approach to lung health in South Africa; PALSA) and to evaluate its effects on respiratory care and detection of tuberculosis among adults attending primary care clinics. DESIGN: Pragmatic cluster randomised controlled trial, with clinics as the unit of randomisation. SETTING: 40 primary care clinics, staffed by nurse practitioners, in the Free State province, South Africa. PARTICIPANTS: 1999 patients aged 15 or over with cough or difficult breathing (1000 in intervention clinics, 999 in control clinics). INTERVENTION: Between two and six educational outreach sessions delivered to nurse practitioners by usual trainers from the health department. The emphasis was on key messages drawn from the customised clinical practice guideline for the outreach programme, with illustrative support materials. MAIN OUTCOME MEASURES: Sputum screening for tuberculosis, tuberculosis case detection, inhaled corticosteroid prescriptions for obstructive lung disease, and antibiotic prescriptions for respiratory tract infections. RESULTS: All clinics and almost all patients (92.8%, 1856/1999) completed the trial. Although sputum testing for tuberculosis was similar between the groups (22.6% in outreach group v 19.3% in control group; odds ratio 1.22, 95% confidence interval 0.83 to 1.80), the case detection of tuberculosis was higher in the outreach group (6.4% v 3.8%; 1.72, 1.04 to 2.85). Prescriptions for inhaled corticosteroids were also higher (13.7% v 7.7%; 1.90, 1.14 to 3.18) but the number of antibiotic prescriptions was similar (39.7% v 39.4%; 1.01, 0.74 to 1.38). CONCLUSIONS: Combining educational outreach with integrated case management provides a promising model for improving quality of care and control of priority respiratory diseases, without extra staff, in resource poor settings. TRIAL REGISTRATION: Current controlled trials ISRCTN13438073.