The role and performance of chest X-ray for the diagnosis of tuberculosis : a cost-effectiveness analysis in Nairobi, Kenya
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Abstract:
From TB suspects attending a chest clinic in Nairobi, Kenya, three sputum specimens were examined for ZN and culture (Lowenstein Jensen) with the objective to compare the performance and cost-effectiveness of two diagnostic pathways. From each suspect a CXR was made using a four point scoring system. Films were re-read by a reference radiologist. HIV test was performed on those who consented. Laboratory and CXR costs were used to compare for cost-effectiveness. Results: Of the 1,389 suspects enrolled, for 998 (72%) data on smear, culture and CXR was complete. 714 films were re-read, showing a 89% agreement (kappa value = 0.75 s.e.0.037) for the combined scores "TB" or "no-TB". The sensitivity/specificity of the CXR score "TB" among smear-negative suspects was 80%/67%. Using chest CXR as a screening tool in all suspects, sensitivity/ specificity of the score "any pathology" was 92%, respectively 63%. The cost per correctly diagnosed case was for the routine process $8.72, compared to $9.27 using CXR as screening tool. When costs of treatment were included, CXR followed by ZN became more cost-effective. Conclusion: The diagnostic pathway ZN followed by CXR was more cost-effective as compared to CXR followed by ZN. When cost of treatment was also considered CXR followed by ZN became more cost-effective. The low specificity of chest X-ray remains a subject of concern. Depending whether CXR was performed on all suspects or on smear-negative suspects only, 22%– 45% of patients labeled as "TB" had a negative culture. The introduction of a well-defined scoring system, clinical conferences and a system of CXR quality control can contribute to improved diagnostic performance.
Authors:
Cleeff, M.R.A. van
,
Kivihya-Ndugga, L.E.
,
Meme, H.
,
Odhiambo, J.A.
,
Klatser, P.R.
Country:
Kenya
Category:
Research
ISSN:
1471-2334
Volume:
5
Journal:
BMC Infectious Diseases
Keywords:
health
,
disease prevention and control
Language:
eng
Organization:
KIT - Royal Tropical Institute
PAGE:
9
Year:
2005
Region:
Africa
,
Africa South of Sahara
,
East Africa
Right:
© 2005 van Cleeff et al. This article is licensed under a Creative Commons Attribution License.
Subject:
Health and Nutrition
Title:
The role and performance of chest X-ray for the diagnosis of tuberculosis : a cost-effectiveness analysis in Nairobi, Kenya