폐기능검사해석에정상하한치변화와새해석흐름도가미치는영향 울산대학교의과대학서울아산병원호흡기내과, 만성기도폐쇄성질환임상연구센터나승원, 오지선, 홍상범, 심태선, 임채만, 고윤석, 이상도, 김우성, 김동순, 김원동, 오연목 Effect of the Changing the Lower Limits of rmal and the Interpretative Strategies for Lung Function Tests Seung Won Ra, M.D., Ji Seon Oh, M.D., Sang-Bum Hong, M.D., Tae Sun Shim, M.D., Chae-Man Lim, M.D., Youn Suck Koh, M.D., Sang Do Lee, M.D., Woo Sung Kim, M.D., Dong-Soon Kim, M.D., Won Dong Kim, M.D., Yeon-Mok Oh, M.D. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and the Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea Background: To interpret lung function tests, it is necessary to determine the lower limits of normal (LLN) and to derive a consensus on the interpretative algorithm. 0.7 of LLN for the FEV 1/FVC was suggested by the COPD International Guideline (GOLD) for defining obstructive disease. A consensus on a new interpretative algorithm was recently achieved by ATS/ERS in 2005. We evaluated the accuracy of 0.7 of LLN for the FEV 1/FVC for diagnosing obstructive diseases, and we also determined the effect of the new algorithm on diagnosing ventilatory defects. Methods: We obtained the age, gender, height, weight, FEV 1, FVC, and FEV 1/FVC from 7362 subjects who underwent spirometry in 2005 at the Asan Medical Center, Korea. For diagnosing obstructive diseases, the accuracy of 0.7 of LLN for the FEV 1/FVC was evaluated in reference to the 5 th percentile of the LLN. By applying the new algorithm, we determined how many more subjects should have lung volumes testing performed. Evaluation of 1611 patients who had lung volumes testing performed as well as spirometry during the period showed how many more subjects were diagnosed with obstructive diseases according to the new algorithm. Results: 1) The sensitivity of 0.7 of LLN for the FEV 1/FVC for diagnosing obstructive diseases increased according to age, but the specificity was decreased according to age; the positive predictive value decreased, but the negative predictive value increased. 2) By applying the new algorithm, 34.5% (2540/7362) more subjects should have lung volumes testing performed. 3) By applying the new algorithm, 13% (205/1611) more subjects were diagnosed with obstructive diseases; these subjects corresponded to 30% (205/681) of the subjects who had been diagnosed with restrictive diseases by the old interpretative algorithm. Conclusion: The sensitivity and specificity of 0.7 of LLN for the FEV 1/FVC for diagnosing obstructive diseases changes according to age. By applying the new interpretative algorithm, it was shown that more subjects should have lung volumes testing performed, and there was a higher probability of being diagnosed with obstructive diseases (Tuberc Respir Dis 2006; 61: 129-136) Key Words: Lung function test, Interpretation, Lower limits of normal, Algorithm. 서 폐활량측정법으로대표되는폐기능검사는호흡기 론 Address for correspondence: Yeon-Mok Oh, M.D. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine 388-1 Pungnap-2dong, Songpa-gu, Seoul, Zip #138-736, Korea Phone : 02-3010-3136, FAX : 02-3010-6968 E-mail : ymoh55@amc.seoul.kr Received : Jun. 27. 2006 Accepted : Jul. 18. 2006 환자의폐기능을정확히평가하고호흡기질환의진단과중등도판정, 그리고경과관찰및치료를판정하는데사용하는중요한검사이다 1. 폐기능검사를해석하는데필수적인사항으로첫째정상예측식 (reference equation) 선정, 둘째정상하한치 (lower limits of normal) 선정, 셋째해석흐름도합의등이다. 첫째, 정상예측식은인종과나라마다차이가나며정상예측식이바뀌면폐기능검사해석에유의하게차이가생기므로정상예측식선정에주의해야한다 2. 둘째, 정상하한치를선정하는방법은세가지가있는데 고정값방법, 95% 신뢰구간방법, 95백분위수 (percentile) 방법 등이다. 예를들면만성폐쇄성폐질 129
SW Ra et al. : Lower limits of normal and interpretative strategies for lung function tests 환 (chronic obstructive pulmonary disease, COPD) 환자의폐쇄성장애를진단하는데는 일초율 (FEV 1 / FVC) < 0.7 방법이국제지침에서권장하는방법인데이방법은정상하한치를고정값인 0.7을사용하고있다 3,4. 하지만, 일초율 (FEV 1 /FVC) 정상하한치를고정값인 0.7로하는것은문제가있는데그이유는연령이증가할수록정상인의일초율정상하한치가감소하는것으로알려져있기때문이다 5,6. 따라서, 연령에따른감소를감안하여일초율정상하한치선정을 95% 신뢰구간방법 이나 95백분위수방법 을사용하는것이더논리적이라고할수있다. 셋째, 최근미국흉부학회 (American Thoracic Society, ATS) 와유럽호흡기학회 (European Respiratory Society, ERS) 가합의하여새폐기능검사해석흐름도를제시하였다 7. 이해석흐름도에의하면과거의해석흐름도와는달리일초율 (FEV 1 /FVC) 이정상하한치이상이고노력성폐활량 (FVC) 이정상하한치미만인환자를바로제한성장애로해석하지않고폐용적검사를추가로시행해서총폐용량 (total lung capacity, TLC) 이정상하한치미만인환자만을제한성장애로해석하고, 반면총폐용량이정상하한치이상인환자는폐쇄성장애로해석하고있다. 따라서, ATS/ERS 새해석흐름도를따를경우폐용적검사를시행해야하는경우가과거해석흐름도를따를경우보다추가로더생기게되며폐쇄성장애로해석해야하는경우도추가로더생기게된다. 본연구에서는정상하한치변화와새해석흐름도가실제폐기능검사해석에어떤영향을미치는지알아보고자하였다. 먼저, 폐쇄성장애를진단하는데정상하한치를고정값방법인 일초율 (FEV 1 /FVC) < 0.7 로하였을때진단의정확도를평가하였다. 또한, ATS/ERS의새해석흐름도를실제환자진료에적용할때폐용적검사를추가로얼마나더해야하는지와폐쇄성장애환자로진단되는경우가얼마나증가하는지알아보았다. 대상및방법서울아산병원에서폐활량측정법을시행한 7362명 ( 대상군 A) 과폐용적검사를시행한 1611명 ( 대상군 B) 을후향적으로연구하였다. 1. 대상 1) 폐활량측정법을시행한환자 ( 대상군 A) 서울아산병원의호흡기검사실에서 2005년 7월 1일부터 11월 30일까지 5개월간폐활량측정법을시행한 8871 명을대상으로하였고이중나이가 20세미만, 외국인, 중복된환자 1509명은대상에서제외하여총 7362명의환자가포함되었다. 반복하여폐활량측정법을시행한경우에는처음실시한폐활량측정법만포함하였다. 상기대상을대상군 A라고정의하였고대상군 A를이용하여 일초율 (FEV 1 /FVC) < 0.7 의정확도를평가하였다. 또한, 대상군 A를이용하여 ATS/ERS 새해석흐름도를적용하였을때폐용적검사를추가로더해야하는경우가얼마나증가하는지연구하였다. 2) 폐활량측정법및폐용적검사를함께시행한환자 ( 대상군 B) 상기대상군 A 중폐활량측정법뿐만아니라폐용적검사도함께같은날시행한 1611 명의환자를대상군 B라고정의하였다. 대상군 B를이용하여 ATS/ERS 새해석흐름도를적용하면폐쇄성장애환자로진단되는경우가얼마나증가하는지연구하였다. 2. 방법 1) 폐활량측정법폐활량측정기 (Vmax22 또는 2130, Sensor Medics, 미국 ) 를사용하여 1초간노력성호기량 (forced expiratory volume in one second, FEV 1 ) 과노력성폐활량 130
Tuberculosis and Respiratory Diseases Vol. 61..2, Aug. 2006 A FEV1/ B FEV1/ rmal Restriction Obstruction Mixed defect rmal Restriction Obstruction Mixed defect Figure 1. Algorithms for the interpretation of lung function tests The left algorithm (A) was suggested by American Thoracic Society(ATS) in 1991; the right (B) by American Thoracic Society/European Respiratory Society(ATS/ERS) in 2005. FEV 1, forced expiratory volume in one second; FVC, forced vital capacity; LLN, lower limits of normal; TLC, total lung capacity (forced vital capacity, FVC) 을측정하였다. 폐활량측정법은미국흉부학회에서권장하는방법으로시행하였다 8. 폐활량측정법정상예측식은최등이보고한한국인의정상예측식을이용하였고정상하한치는 95백분위수방법으로선정하였다 9. 95백분위수방법으로선정하였을때정상하한치는일초율 (FEV 1 /FVC) 의경우남자는 91.1% 예측치이고여자는 89.9% 예측치이다 9. 2) 폐용적측정법폐용적측정기 (6200 Body Box, Sensor Medics, 미국 ) 를사용하여총폐용량 (total lung capacity, TLC) 을측정하였다. TLC 정상예측식으로우리나라예측식이없어서유럽석탄철강공동체 (European Community for Steel and Coal, ECSC) 의예측식을사용하였고, 정상하한치는 95% 신뢰구간법을사용해서구하였다 10,11. 3) 폐쇄성장애진단에 일초율 (FEV 1 /FVC) < 0.7 의정확도평가폐쇄성장애를진단하는황금기준 (gold standard) 을 일초율 (FEV 1 /FVC) < 5 백분위수 로하였을때 일초율 (FEV 1 /FVC) < 0.7 의정확도를평가하였다. 4) 해석흐름도새해석흐름도는 2005년미국흉부학회와유럽호흡기학회가공동으로권장한것을사용하였다 7 (Figure 1). 이새해석흐름도와 1991년도미국흉부학회에서권장한과거의해석흐름도 5 와비교하였다. 결과 1. 대상환자특성 1) 폐활량측정법을시행한환자 ( 대상군 A) 대상군 A의평균연령은 59.8세이었다. 대상환자 7362 명중 4204명은남자이고 3158명은여자이었다. Table 1. Characteristics of the subjects (group A) Men Women Number 4204 3158 Age (years) 60.4 ± 12.6* 58.9 ± 13.0 Height (cm) 167.4 ± 6.1 154.7 ± 5.9 Weight (kg) 65.7 ± 10.6 56.9 ± 9.0 FEV 1/FVC (% Pred ) 95.5 ± 18.9 100.9 ± 13.3 FEV 1 (% Pred) 77.6 ± 21.6 85.7 ± 20.3 FVC (% Pred) 80.5 ± 16.2 84.0 ± 16.2 * Mean ± standard deviation % Predicted value 131
SW Ra et al. : Lower limits of normal and interpretative strategies for lung function tests Table 2. Characteristics of the subjects (group B) Men Women Number 1062 549 Age (years) 61.4 ± 12.3* 56.7 ± 12.8 Height (cm) 167.2 ± 6.1 155.0 ± 6.0 Weight (kg) 65.6 ± 11.0 56.2 ± 8.3 FEV 1/FVC (% Pred ) 90.7 ± 21.4 96.0 ± 16.3 FEV 1 (% Pred) 68.0 ± 21.0 72.5 ± 19.9 FVC (% Pred) 74.7 ± 17.0 75.5 ± 17.3 TLC (% Pred) 85.3 ± 18.6 84.8 ± 18.2 * Mean ± standard deviation % Predicted value Figure 3. Positive predictive value(ppv) and negative predictive value(npv) of FEV 1 /FVC < 0.7 diagnosing obstructive diseases. Spirometry was performed for 7362 patients from July 1 to vember 30, 2005 in the Asan Medical Center. FEV 1/FVC < 5 th percentile was used as the gold standard to define obstructive diseases. 2. 폐쇄성장애진단에 FEV 1 /FVC < 0.7 의정확성 Figure 2. Sensitivity and specificity of FEV 1/FVC < 0.7 diagnosing obstructive diseases. Spirometry was performed for 7362 patients from July 1 to vember 30, 2005 in the Asan Medical Center. FEV 1/FVC < 5 th percentile was used as the gold standard to define obstructive diseases. 대상환자의 FEV 1 /FVC, FEV 1, FVC의평균 ( 표준편차 ) 은각각 97.8(16.9)% 예측치, 81.0(21.5)% 예측치, 82.0(16.3)% 예측치이었다 (Table 1). 폐쇄성장애진단에 FEV 1 /FVC < 0.7 의민감도와특이도는연령이내려갈수록민감도는감소하였으나특이도는증가하였다. 반면연령이올라갈수록민감도는증가하였으나특이도는감소하였다 (Figure 2). FEV 1 /FVC ratio < 0.7 의양성예측도와음성예측도는연령이내려갈수록양성예측도는증가하였으나음성예측도는감소하였다. 연령이올라갈수록양성예측도는감소하였고음성예측도는증가하였다 (Figure 3). 3. ATS/ERS 새해석흐름도적용시영향 2) 폐활량측정법및폐용적검사를같은날시행한환자 ( 대상군 B) 대상군 B의평균연령은 59.8세이었다. 대상환자 1611명중 1062명은남자이고 549명은여자이었다. 대상환자전체의 FEV 1 /FVC, FEV 1, FVC, TLC의평균 ( 표준편차 ) 은각각 92.5(20.0)% 예측치, 69.5(20.8)% 예측치, 75.0(17.1)% 예측치, 85.1(18.4)% 예측치이었다 (Table 2). 1) 폐용적검사를추가로해야하는경우증가과거의해석흐름도를적용할경우 14.5%(1070명 /7362명) 만폐용적검사가필요하였는데, 새 ATS/ ERS 해석흐름도를적용할경우 34.5%(2540명 /7362 명 ) 의환자가추가로폐용적검사가필요하였다. 결과적으로전체환자의 49% 가폐용적검사가필요하였다 (Figure 4). 132
Tuberculosis and Respiratory Diseases Vol. 61..2, Aug. 2006 7362 FEV1/ 1611 FEV1/ 5575 1787 1018 593 681 191 402 rmal TLC Obstruction TLC 3035 2540(34.5%) 717 1070(14.5%) Figure 4. Application of the new ATS/ERS algorithm for the interpretation of lung function tests requires that 34.5% of subjects should perform additional lung volumes testing to obtain TLC. The numbers in the algorithm represent numbers of subjects in each flow; the percentages in parentheses represent percentage of subjects to all subjects (n=7362). For the 7362 subjects, spirometry was performed from July 1 to vember 30, 2005 in the Asan Medical Center. FEV 1, forced expiratory volume in one second; FVC, forced vital capacity; LLN, lower limits of normal; TLC, total lung capacity; ATS/ERS, American Thoracic Society/European Respiratory Society 2) 폐쇄성장애로진단되는환자의증가새 ATS/ERS 해석흐름도를적용할경우, 과거에제한성질환으로진단되었던환자중 30%(205명 /681 명 ) 가폐쇄성질환으로진단되었고이는전체환자의 13%(205명 /1611명) 에해당하였다 (Figure 5). 고 본연구결과에의하면만성폐쇄성폐질환 (chronic obstructive pulmonary disease, COPD) 에대한지침서에서권장하는폐쇄성장애진단기준인 FEV 1 /FVC < 0.7 4 의정확성은 50~69세환자에서높게나왔다. 50~69세의경우진단의정확성이민감도와특이도모두 80% 를넘었다. 하지만, 이보다연령이작을때는민감도가낮은문제가있고 70세이상인경우는특이도가낮은문제가있다. 따라서, 폐쇄성질환진단기준으로 FEV 1 /FVC < 0.7 을사용하였을때연령에따라서민감도와특이도가변한다는것을염두에두고실제환자진료에적용하는것이필요하겠다. 찰 337(21%) 476(30%) 205 684(42%) 288 rmal Restriction Obstruction Mixed defect 114(7%) Figure 5. Application of the new ATS/ERS algorithm for the interpretation of lung function tests revealed that additional 205 subjects were diagnosed as obstructive diseases. The numbers in the algorithm represent numbers of subjects in each flow; the percentages in parentheses represent percentage of subjects to all subjects (n=1611). For the 1611 subjects, both spirometry and lung volumes testing were performed on the same date from July 1 to vember 30, 2005 in the Asan Medical Center. FEV 1, forced expiratory volume in one second; FVC, forced vital capacity; LLN, lower limits of normal; TLC, total lung capacity; ATS/ERS, American Thoracic Society/European Respiratory Society. 또한, 본연구결과에의하면새로운 ATS/ERS 폐기능검사해석흐름도를실제환자진료에적용할때 34.5% 의환자가추가로폐용적검사를시행해야하고과거의해석흐름도로해석하면제한성장애로진단되던환자중 30%( 전체환자중 13%) 가폐쇄성장애로진단되는것을확인할수있었다. 이결과는단지해석흐름도만을바꾸었을때실제환자진료에상당히영향을미칠수있다는것을의미한다. 본연구에서는연구대상으로두개의군을사용하였다. 대상군 A는일정기간동안폐활량측정법을시행한사람이고대상군 B는대상군 A 중폐용적검사를폐활량측정법시행일에함께시행한사람이다. 대상군 A를이용하여 일초율 (FEV 1 /FVC) < 0.7 의정확성을평가하였고 ATS/ERS 새해석흐름도를적용하였을때폐용적검사를추가로더해야하는경우가얼마나증가하는지연구하였다. 한편, ATS/ERS 새해석흐름도를적용하면폐쇄성장애환자로진단되는경우가얼마나증가하는지알아보려면, 폐용적을측 133
SW Ra et al. : Lower limits of normal and interpretative strategies for lung function tests 정한사람을연구대상으로필요하게되므로대상군 A 대신폐용적을측정한사람인대상군 B를이용하였다. 대상군 B는대상군 A 보다폐기능이더나쁜것같은데이는폐질환을의심하는경우에담당의사가폐용적을측정하였을가능성이있기때문일것이다 (Table 1 & 2). 미국흉부학회에서는폐활량측정법정상예측식을선택할때인종과연령, 성별, 신장, 생활환경등의특수성을고려해야한다고권고하고있다 5. 최근우리나라전체인구중표본추출하여폐활량측정법을시행하였고이를통해서한국인폐활량측정법정상예측식이개발되었다 9. 한편, 한국인폐용적검사정상예측식은아직개발되지않았기때문에기존에많이사용하는정상예측식중하나인유럽석탄철강공동체 (European Community for Steel and Coal, ECSC) 의정상예측식을본연구에서사용하였다. FEV 1 /FVC의정상하한치가연령이증가함에따라감소한다는것은이미잘알려진사실이다 5. 하지만, COPD 국제지침인 GOLD(Global Initiatives for Obstructive Lung Diseases) 에서는 FEV 1 /FVC 정상하한치로고정값인 0.7을사용하였다 4. 이렇게 FEV 1 /FVC 정상하한치로 0.7을사용하면간편하다는장점과정상예측식이필요없다는장점이있기는하지만본연구결과에서알수있듯이 70세이상이거나 50세이하인경우정확성이떨어진다는것을유념해야할것이다. 이결과는연령이증가하면 FEV 1 /FVC < 0.7 의위양성률이높아진다는다른연구자들의보고와도부합하는내용이다 12. 따라서, FEV 1 /FVC < 0.7 기준은연령이많고증상이없는비흡연자를만성폐쇄성폐질환으로과잉진단할위험이있다 13. 본연구결과에의하면, FEV 1 /FVC < 5 백분위수 를황금기준으로할때폐쇄성장애를진단하는데 FEV 1 /FVC < 0.7 의정확성이높게나온연령층은 50~69 세이었고이연령층은만성폐쇄성폐질환의유병률이높고폐기능검사를가장많이하는연령층이었다. 새로운 ATS/ERS 폐기능검사해석흐름도에서는흡기폐활량 (inspiration vital capacity, IVC), 서서히호기하는호기폐활량 (slow expiration vital capacity, SVC) 또는 FVC중가장큰값을사용하도록권고하 고있다. 기류폐쇄가있는경우 FVC는대개 IVC 또는 SVC보다작지만 14, 아직까지 IVC나 SVC에대한한국인의정상예측식이없어서본연구에서는한국인의정상예측식이있는 FVC를사용하였다. FEV 1 과 FVC가동시에감소되어있어서 FEV 1 / FVC 비가정상인경우해석에주의가필요하다. 대개는환자가완전하게흡기와호기를하지못한경우가많으나기류속도가너무느려서잔기량 (residual volume, RV) 까지충분히길게내쉬지못해서발생할수있다. 또다른이유로호기시에소기도가일찍부분적허탈 (patchy collapse) 이발생하여이러한양상을보일수있다 15-18. 소기도질환환자의폐기능검사에서 RV는증가, VC는감소되고 TLC는정상소견을보였다 17-19. 새로운 ATS/ERS 폐기능검사해석흐름도에서는 FEV 1 /VC 비는정상하한치이상이면서 VC 가감소되어있는경우 TLC를시행해서정상이면폐쇄성장애로해석하고있다. 본연구결과를보면, 새해석흐름도를실제환자진료에적용하게되면과거해석흐름도에의하면제한성장애로진단할환자의 30%(205명 /681명) 가폐쇄성장애로해석이바뀌게되는것을보여주었다. 이렇게해석이바뀌는환자를대상으로병력, 폐기능검사, 흉부엑스선, 경과등임상적인자료를분석하여연구하는것이향후필요하리라사료된다. 그래야만, 이렇게해석이바뀌는환자중실제폐쇄성장애가있는환자가얼마나되는지추정해볼수있기때문이다. 향후실제환자를진료할때새로운해석흐름도를적용하기위해서는추가적인임상적자료를분석, 평가하는것이필요하고폐용적검사의비용-편익 (cost-benefit) 에대해서도고려하여야할것으로사료된다. 본연구의제한점은폐쇄성질환을확진하는정확한방법이없었다는것이다. 정확한폐쇄성질환진단법이없음은 FEV 1 /FVC < 0.7 방법의정확성연구와새로운 ATS/ERS 폐기능검사해석흐름도적용연구를수행하면서결론을정확히내리기어려운근원적인문제점이었다. 본연구에서사용한황금기준인 FEV 1 /FVC < 5 백분위수 방법이정확히폐쇄성질환을진단할수있는지평가된적이저자가알기로는아 134
Tuberculosis and Respiratory Diseases Vol. 61..2, Aug. 2006 직없는것같다. 마찬가지로새로운 ATS/ERS 폐기능검사해석흐름도를적용하였을때정확히폐쇄성질환을진단할수있는지평가된적도역시없는것같다. 따라서, 폐쇄성질환을진단할수있는정확한방법을개발하는것이향후중요한연구주제중하나가될것이다. 또한, 본연구의제한점으로는 TLC의한국인정상예측식이없어서유럽석탄철강공동체의정상예측식을사용하였다는점과 VC 대신 FVC를사용하였다는점, 그리고폐기능검사외의다른임상정보나방사선소견을평가하지는않았기때문에새로운 ATS/ERS 해석흐름도가실제장애양상을진단하는데과거해석흐름도보다더우월한지파악할수없었다는점등이다. 결론적으로, 폐쇄성질환진단기준으로 FEV 1 /FVC < 0.7 을사용하였을때연령에따라서민감도와특이도가변한다는것을염두에두고실제환자진료에적용하는것이필요하겠다. 또한, 새로운 ATS/ERS 해석흐름도를실제환자를진료하는데적용하면폐용적검사를시행해야하는경우가증가하게되고폐쇄성장애로진단되는경우가더증가하게됨에유의해야하겠다. 요약연구배경 : 폐기능검사를해석하는데정상하한치 (lower limits of normal) 선정과해석흐름도합의가필수적이다. COPD 국제지침은 FEV 1 /FVC 정상하한치로 0.7을사용하여폐쇄성장애를진단한다. 한편, 미국흉부학회 (ATS) 와유럽호흡기학회 (ERS) 공동으로새해석흐름도를제시하였다. FEV 1 /FVC 정상하한치 0.7 의정확성과새해석흐름도가실제폐기능검사해석에어떤영향을미치는지알아보고자하였다. 방법 : 서울아산병원의호흡기검사실에서 2005년 7월 1일부터 11월 30일까지 5개월간폐활량측정법을시행한 7362명을대상으로하여 FEV 1 /FVC 정상하한치 0.7 의정확성을평가하였고새로운 ATS/ERS 해석흐름도에따르면폐용적검사가추가로필요한경우가얼마나증가하는지평가하였다. 상기기간내에같은날폐용적검사를시행한 1611 명을대상으로과거해석흐름도와비교하여새로운 ATS/ERS 해석흐름도를적용하게되면폐쇄성장애로진단되는경우가얼마나증가하는지알아보았다. 결과 : 1) FEV 1 /FVC < 0.7 에의한폐쇄성장애진단은연령이증가할수록민감도는증가하였으나특이도는감소하였고양성예측도는감소하였으나음성예측도는증가하였다. 2) 새 ATS/ERS 해석흐름도를적용할경우 34.5% (2540명/7362명) 의환자가추가로폐용적검사가필요하였다. 3) 새 ATS/ERS 해석흐름도를적용할경우, 과거에제한성질환으로진단되었던환자중 30%(205명 /681명) 가폐쇄성질환으로진단되었고이는전체환자의 13%(205명 /1611명) 에해당하였다. 결론 : 폐쇄성질환진단기준으로 FEV 1 /FVC < 0.7 을사용하였을때연령에따라서민감도와특이도가변한다. 또한, 새로운 ATS/ERS 해석흐름도를실제환자를진료하는데적용하면폐용적검사를시행해야하는경우가증가하게되고폐쇄성장애로진단되는경우가더증가하게된다. 감사의글 본연구는보건복지부보건의료기술진흥사업의지원에의하여이루어진것임 (0412-CR03-0704-0001) 참고문헌 1. Gold WM. Pulmonary function testing. In: Murray JF, Nadel JA, editors. Textbook of respiratory medicine. 4th ed. Philadelphia: Saunders; 2005. p. 671-733. 2. Oh YM, Hong SB, Shim TS, Lim CM, Koh YS, Kim WS, et al. Effect of a new spirometric reference equation on the interpretation of spirometric patterns and disease severity. Tuberc Respir Dis 2006;60: 215-20. 3. American Thoracic Society/European Respiratory Society Task Force. Standards for the diagnosis and management of patients with COPD [Internet]. Version 1.2. New York: American Thoracic Society; 2004 [updated 2005 September 8]. Available from: http:// 135
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