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.

(Go to page 13) (Go to page 14) (Go to page 16) (Go to page 20) Symptoms present < 2 weeks Symptoms present 2 weeks ≥ Consider (Go to page 15)

Chronic Bronchitis
Consider (Go to page 12)

Asthma or COPD
Go to page 2

Cough AND/OR Difficult breathing (defined as breathlessness at rest or on activity, wheeze and/or tight chest)
If the purpose of this visit is to treat and assess: If poor compliance and/or technique instruct patient on correct drug usage. Give 40mg of prednisone orally (once daily) for 7 days to patients with the following: History of recent emergency visits for asthma.
Worsening of asthma symptoms in the months or weeks prior the onset of the acute attack.
History of previous hospital or intensive care unit admission for asthma. If the patient reports a cough with new or increased sputum production and/or change in sputum colour (yellow, green) and/or fever, add Amoxycillin 500mg three times a day for 7 days OR if penicillin-allergic, Erythromycin 500mg four times a day for 7 days.
If the underlying lung condition is unknown, go to page 12 to make diagnosis.
Encourage all patients to stop smoking cigarettes, pipes or dagga.
Book follow-up visit before medicines are expected to run out.

Symptoms get worse.
Not better after a course of oral prednisone has been completed.  Instruct patient to mix 1/2 teaspoon salt + 1 teaspoon bicarbonate of soda in 500ml lukewarm water. Sniff up each nostril every 4-6 hours. OR 0.9% Sodium chloride drops in each nostril every 4-6 hours.

no longer REASSURE PATIENT THAT ANTIBIOTICS ARE NOT NECESSARY.
Amoxycillin 500mg orally three times a day for 10 days OR If penicillin-allergic, give cotrimoxazole (Bactrim) 2 tablets (80/400mg) twice a day for 5 days.

no longer
Refer if: 0.9% Sodium chloride drops in each nostril every 4-6 hours.
Swelling around eye or face. Failure to respond to medication after 10 days.

MILDLY ILL PATIENT PAIN AND/OR TENDERNESS OVER SINUSES: WITH ACUTE SINUSITIS
Clear nasal discharge. Mild pain over sinuses.

≥
Severe symptoms regardless of duration. Pussy nasal discharge. Face or tooth pain and tenderness.

RED THROAT WITHOUT PUS
Salt water mouthwash (1/2 teaspoon salt in a glass of warm water). Gargle twice a day.

REASSURE PATIENT THAT ANTIBIOTICS ARE NOT NECESSARY.
Salt water mouthwash (1/2 teaspoon salt in a glass of warm water). Gargle twice a day.
OR If penicillin-allergic, give Erythromycin 250mg 6 hourly before meals for 10 days.
More than 4 documented episodes per year.

Refer if:
Severe swallowing problems. Inability to open mouth.
Nystatin lozenges 100 000 IU -4 times a day for 10 days. OR Nystatin 100 000 IU/ml 1-2 ml 4 times a day for 10 days. Roll a piece of paper towel into a wick.
Insert wick into ear and remove once it is wet.
Repeat 4 times a day until ear is dry.
Insert acetic acid ear drops if indicated (go to page 10) -4 drops in affected ear.
Never leave the wick or any other object inside the ear.

DIAGNOSING OBSTRUCTIVE LUNG DISEASE
It is not always easy to decide whether a patient has asthma or COPD as the symptoms may be similar, or both diseases may be present. A few questions may help with the diagnosis.

Ask if:
TREAT AS ASTHMA.

REFER TO DOCTOR WITHIN 1 MONTH Go to page 13
Symptoms started during childhood or early adulthood.
History of hayfever, eczema and/or allergies.
Family history of asthma.
Symptoms only during attacks with periods of normal breathing in between.
Symptoms are usually worse: at night; in the early hours of the morning; during an upper respiratory tract infection or when the weather changes.
Symptoms improve or disappear after using inhaler.

Ask if:
Symptoms started later in life (usually after the age of 35 years).
Symptoms slowly worsened over a long period of time.
Long history of daily or frequent cough and sputum production (usually starts long before the onset of shortness of breath).
Short of breath for most of the day, rather than at night or during the early hours of the morning only.
History of heavy smoking eg. more than 20 cigarettes / day for 15 years or more.

TREAT AS COPD. REFER TO DOCTOR WITHIN 1 MONTH.
Go to page 14 (If unsure, treat as asthma)

12
If 1 feature of asthma, and no significant history of smoking, consider a cardiac or non-lung cause of breathlessness, especially if associated hypertension, ischaemic heart disease and/or diabetes mellitus.

MANAGEMENT OF CHRONIC ASTHMA
The aim of asthma management is to obtain complete control of all features of asthma. Aim for: 1) Minimal (ideally no) daytime and night time symptoms 2) Minimal or no exacerbations (asthma attacks) 3) Minimal need for quick-relief medications 4) No limitations of daily activities

IF COMPLETE CONTROL AT ANY LEVEL OF TREATMENT
Continue current medication. At next visit, reduce treatment to previous level (step-down) if control is still complete. Schedule next appointment.

IF POOR CONTROL AT ANY LEVEL OF TREATMENT
Increase to next level of treatment (step-up). Consider adding prednisone 40mg orally once daily for 7 days and reassess in 1 month.

Doctor to initiate
Refer if poor control despite stepping-up. Strongly urge the patient to quit. :

SYMPTOMS 2 WEEKS ≥
Determine willingness to make a quit attempt. : Help the patient to quit. : Schedule follow-up contact.
The aim of COPD management is to:

SEVERE COPD WITH COMPLICATIONS
Encourage patients to stop smoking in order to prevent worsening of disease. Improve symptoms with inhaled bronchodilators. Recognise and treat acute exacerbations early.
(up to 4 times per day) (up to 4 times per day) Amoxycillin 500mg three times a day for 7 days OR If penicillin-allergic, Erythromycin 500mg four times for 7 days.

CHRONIC COUGH WITH OR WITHOUT SPUTUM PRODUCTION; NO BREATHLESSNESS: CHRONIC BRONCHITIS
Usually in heavy smokers, or those with lung damage. Daily cough with or without sputum production for months or years. Usually begins in middle or old age. Heavy occupational (dust, mines, industry) or domestic air pollution (indoor fires or gas stoves) exposure in some.

Refer:
All patients should be advised to stop smoking. If possible, avoid domestic pollution, occupational exposure and substance abuse (eg. dagga).
If no history of smoking. ≥

Patient:
Must stand in a wellventilated room or outside.
Rinse mouth with water.
Take a deep breath, and cough forcibly.

Nurse:
Must not stand in front of patient during the procedure.
Replace and secure the lid immediately. Wash hands after handling specimen. Place specimen in bag and store in fridge while awaiting collection.

* According to the South African Tuberculosis Control Practical Guidelines 2000
Test sputum: Label bottles before dispensing them to patients.

Sputum (AFB+AFB+)
CXR report does not suggest active TB or other condition requiring immediate referral.
Repeat 1 sputum for AFBs Schedule follow-up
CXR report suggests TB.

Sputum AFB+
Sputum AFB-Give Amoxycillin 250 mg orally 3 times a day for 7 days. Schedule follow-up.

Sputum AFB-
Refer to medical officer for CXR +\-culture

LOOK FOR
White patches in the mouth, which are scratched off with difficulty, causing bleeding Painful rash with blisters, confined to one part of the body Bluish-black patches or lumps on skin or mouth . Evidence of severe loss of weight. Genital ulcers or discharge.

INFORM ABOUT VOLUNTARY CONFIDENTIAL COUNSELLING AND TESTING (VCCT)
Educate patient about HIV/AIDS, methods of transmission and risk factors. Explain about VCCT: What the results means.
Who will perform the counselling and the testing. That it is completely voluntary. That testing is confidential. How testing is done. When and how results are given.
If patient agrees to have VCCT, refer to the lay counsellor for testing. If a lay counsellor is not available, refer to health facility where testing is available.
Painless swollen glands Long history of diarrhoea History of engaging in high-risk behaviour (eg. Vaginal, anal or oral sex without a condom)

HIV POSITIVE HIV NEGATIVE
Establish a relationship with the patient and encourage regular follow-up. Respect his/her right to confidentiality.
Refer to the lay counsellor should the patient require further counselling. Encourage safer-sex practices.
Provide medical care at each visit. Look for and treat HIV-related diseases.
Encourage safer sex practices.

ORAL THRUSH/CANDIDA
Go to page 9

Refer:
For exclusion of extrapulmonary TB.