Evidence Based MedicineClinical Management of Pulmonary Tuberculosis

Section C Maranion – Mendoza

Case:

Subjective

Pertinent Positive Pertinent Negative

•28 y/o female•CC: Hemoptysis•Chronic cough

• No weight change• No change in eating habits

•2 months PTC:

•Coughing intermittently (last 2 mos)•Cough = productive of scanty whitish to yellowish sputum• Occasionally took ginger ale afforded temporary relief• 1 month PTC:

•Intermittent low grade fever, malaise and night sweats

• Recently: back pains, blood-streaked sputum

Salient features

• 28 y/o female• Chronic cough & Hemoptysis• Cough = productive of scanty whitish

to yellowish sputum• Intermittent low grade fever, malaise

and night sweats• back pains• No weight change

Evidence Based Approach

Diagnosis

Treatment

Possible Harm

Prognosis

1.Clinical impression2.Most probable diagnosis3.Critical appraisal of an article

about a diagnostic test

DIAGNOSIS

Karmi Margaret MarcialMichelle MatematicoEvangelyn Grace MatiasMarienelle Maulion

Clinical Impression

Bronchiectasis Lung Cancer Tuberculosis

Chief complaint:Hemoptysis

Page _______Diagnosis - 1

Differential DiagnosisT. B. (The Patient ) Bronchiectasis Lung Cancer Pulmonary

Tuberculosis

28 y/o, female Higher incidence adolescence and early adulthood. Higher incidence in 25-34 y/o female

Chronic cough(yellow sputum)

persistent orrecurrent cough and purulent sputum production

cough,

hemoptysis,

post-obstructive pneumonitis (fever and productive cough).

Cough (purulentSputum)

Hemoptysis Hemoptysis occursin 50 to 70% of cases

Hemoptysis (can be massive)Blood streaking of the sputum is frequently documented

Low grade fever Fever Fever (oftenlow-grade and intermittent)

Malaise, Night sweats General malaise and weakness, Night sweats

(-) weight loss / change in eating habits

Weight loss Weight loss and anorexia

Probability 50% 30% 60%

Testing Thresholds and Pre-Test Probabilities

10%

80%

60%

TB

10%

80%

50%

Bronchiectasis

10%

90%

30%

Lung CA

0%

100%

10% 80%

60%

TB

MOST PROBABLE DIAGNOSIS:

Script page

In this scenario, we consider the probability the probability of ____% that the patient has TB.

We also consider institutional care for these patients if the probability is _______%

Maybe home intervention if probability is _____%

Assessment of Clinical Scenario

Diagnostic options for TB

Diagnostic techniques

Page _______

Search

Candidate Journals

Clinical scenario or question

What is the accuracy of HRCT or CXR in diagnosis of pulmonary tuberculosis?

The Article

***

Validity

Was there an independent, blind comparison with a reference standard?

Yes. The pulmonologist and radiologist who independently interpreted the HRCTs were unaware of the patients’ clinical condition.

Critical Apprai

sal

Validity

Was the diagnostic test evaluated in an appropriate spectrum of patients (like those in whom we would use it in practice?)

Yes. In a 2500-bed medical center in Southern Taiwan, the study group of 157 with suggestive CXR consisted of 33 women and 124 men with an age range of 20 to 83 years.

Critical Apprai

sal

Validity

Was the reference standard applied regardless of the diagnostic test result?

Yes. Sputum culture and AFB smear microscopy were performed in diagnosing active PTB prior to subjecting the patients to HRCT.

Critical Apprai

sal

Validity

Was the test validated in a second, independent group of patients?

No. Chest X-ray and HRCT were performed on the same set patients.

Critical Apprai

sal

Clinical Importance

What is the sensitivity? CXR: 57% HRCT: 89% What is the specificity? CXR: 28% HRCT:85% Can you calculate a likelihood ratio,

or is there one already calculated? Yes. It can be calculated in CXR and

HRCT

Critical Apprai

sal

Clinical Importance: Xray

Page _______

Clinical Importance: Xray

Sensitivity = 57% Specificity = 28% LR+ = 0.80 LR- = 1.52

(+) Dse (-) Dse Total

Xray (+) 32 66 98

Xray (-) 24 26 50

Total 56 92 148

Clinical Importance: Xray

Testing Thresholds: X-ray

Positive Post-Test Probability = 55% Negative Post-Test Probability = 70%

10% 80%

60%

TB

55% 70%

Clinical Importance: HRCT

Page _______

Clinical Importance: HRCT

Sensitivity = 89% Specificity = 85% LR+ = 5.81 LR- = 0.13

(+) Dse (-) Dse Total

HRCT (+) 56 13 69

HRCT (-) 7 72 79

Total 63 85 148

Clinical Importance: HRCT

Testing Thresholds: HRCT

Positive Post-Test Probability = 90% Negative Post-Test Probability = 16%

Xray HRCT

10% 80%

60%

TB

55% (+)

70% (-)

90% (+)

19% (+)

Applicability

In our practice, is the test:

Available? Yes. It is available in USTH.

Affordable? No. HRCT plain costs P 8000; with contrast P15,275.

Accurate? Yes. The accuracy of the test based on the pulmonologist’s interpretation is 86% and radiologist’s interpretation is 90%.

Precise? Yes.

Critical Apprai

sal

Applicability

Can we generate a reasonable pre-test probability in our clinical scenario?

Yes. The pre-test probability was generated based on the manifestation of the patient.

Are the study patients similar to our own? Yes. The study patients are similar on our own,

using the patient’s age and gender as the basis.

Has anything changed since the study was published?

None.

Critical Apprai

sal

Applicability

Will the resultant post-test probabilities change our management?

Yes. It will lead the physician decide to give the treatment or not.

Critical Apprai

sal

TREATMENT

Jhudielle MedenillaKristianne Rachelle MedinaCarmelou Mae Mejino

HARM

Ivy MelgarejoAlvin MendozaDonne Paolo Mendoza

PROGNOSIS

Ma. Cristina MaranionEric John MarayagPamela Marcelo