The Cost-Effectiveness of Chest Radiography as a Screen ing Test for Chronic Obstructive Pulmonary Disease among the Bangkok Elderlyt
BENJAMAS CHUAYCHOO, MD*, NANTA MARANETRA, MD, FRACP, FRCP*, JARIYA LERTAKYAMANEE, MD**, CHANA NARUMAN, MSc*, W ANCHAI DEJSOMRITRUTA I, MD*, TRONGTUM TONGDEE, MD***, NITIPATANA CHIERAKUL, MD*, ARTH NANA, MD*, WISANU THAMLIKITKUL, MD****, T ASNEEY A SUTHAMSMAI, MSc*, SUTEE SAENGKAEW, BN*, WICHEAN SREELUM, Dip.MST* MONTCHAI AKSORNIN, Dip.AN*, AMOLWAN DECHAPOL, BA* CHAIRAT REUNGCHAM, Dip.AN*
Affiliation : * Division of Respiratory Disease and Tuberculosis, Department of Medicine, ** Department of Anaesthesiology, *** Department of Radiology, **** Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. t Financially supported by National Research Council of Thailand.
There were 3,094 subjects who participated, completed spirometry and a CXR. The selected nine indices from PA and lateral CXR for diagnosing COPD were based on the presence of hyperinfla tion. The positive criteria of each index were reported.
The cut-off point of best average accuracy ie. Z score of the CXR was 0.07 with a sensitivity of 75.9 per cent (95% CI 70.2-81.6% ), specificity of 72.4 per cent (95% CI 70.8-74.0%) and the best average accuracy of 74.1 per cent (95% CI 72.5-75.7%) whereas the cost-effective cut-off point of a Z score of CXR as a screening test for COPD was 0.04 at the lowest grand total cost. The cost to detect one case of COPD was 2,008 baht and needed to screen 17 elderly. It is suggested that CXR is probably not a suitable screening test for COPD in the elderly due to the complicated derivation of the CXR indices. However, its efficacy may be of some value in in-office diagnosis of COPD.
Keywords : COPD, Elderly, Cost-Effectiveness, Chest Radiography, Screening
