DOI: 10.4046/trd.2009.67.2.88 ISSN: 1738-3536(Print)/2005-6184(Online) Tuberc Respir Dis 2009;67:88-94 CopyrightC2009. The Korean Academy of Tuberculosis and Respiratory Diseases. All rights reserved. Reserch Article 가정산소치료의보험급여실시이후처방실태 : 다기관조사 - 만성기도폐쇄성질환임상연구센터제 3 세부과제만성기도폐쇄성질환진료지침개발 / 보급연구 - 1 경희대학교의과대학, 2 가톨릭대학교의과대학, 3 고려대학교의과대학, 4 동국대학교의과대학, 5 영남대학교의과대학, 6 이화여자대학교의과대학, 7 전남대학교의과대학, 8 한양대학교의과대학, 9 한림대학교의과대학내과학교실박명재 1, 유지홍 1, 최천웅 1, 김영균 2, 윤형규 2, 강경호 3, 이승룡 3, 최혜숙 4, 이관호 5, 이진화 6, 임성철 7, 김유일 7, 신동호 8, 김태형 8, 정기석 9, 박용범 9 Long-term Oxygen Therapy for Chronic Respiratory Insufficiency: the Situation in Korea after the Health Insurance Coverage: a Multi-center Korean Survey -Study for the Development and Dissemination of the COPD Guidelines, Clinical Research Center for Chronic Obstructive Airway Disease- Myung Jae Park, M.D. 1, Jee-Hong Yoo, M.D. 1, Cheon Woong Choi, M.D. 1, Young Kyoon Kim, M.D. 2, Hyoung-Kyu Yoon, M.D. 2, Kyung Ho Kang, M.D. 3, Sung Yong Lee, M.D. 3, Hye Sook Choi, M.D. 4, Kwan Ho Lee, M.D. 5, Jin Hwa Lee, M.D. 6, Sung-Chul Lim, M.D. 7, Yu-Il Kim, M.D. 7, Dong Ho Shin, M.D. 8, Tae-Hyung Kim, M.D. 8, Ki-Suck Jung, M.D. 9, Yong Bum Park, M.D. 9 Department of Internal Medicine, 1 Kyung Hee University, 2 The Catholic University of Korea, 3 Korea University, Seoul, 4 Dongguk University, Gyeongju, 5 Yeungnam University, Daegu, 6 Ewha Womans University, Seoul, 7 Chonnam University, Gwangju, 8 Hanyang University, Seoul, 9 Hallym University, Chuncheon, Korea Background: From November 2006, The national health insurance system in the Republic of Korea began to cover prescribed long-term oxygen therapy (LTOT) in patients with chronic respiratory insufficiency. This study examined the current status of LTOT after national health insurance coverage. Methods: Between November 1, 2006 and June 30, 2008, the medical records of patients who were prescribed LTOT by chest physicians were reviewed. The data was collected from 13 university hospitals. Results: 197 patients (131 male and 66 female) were prescribed LTOT. The mean age was 64.3±13.0 years. The most common underlying disease was chronic obstructive pulmonary disease (n=103, 52.3%). Chest physicians prescribed LTOT using arterial blood gas analysis or a pulse oxymeter (74.6%), symptoms (14%), or a pulmonary function test (11.2%). The mean oxygen flow rate was 1.56±0.68 L/min at rest, 2.08±0.91 L/min during exercise or 1.51±0.75 L/min during sleep. Most patients (98.3%) used oxygen concentrators. Only 19% of patients used ambulatory oxygen supplies. The oxygen saturation before and after LTOT was 83.18±10.48% and 91.64±7.1%, respectively. After LTOT, dyspnea improved in 81.2% of patients. The mean duration of LTOT was 16.85±6.71 hours/day. The rental cost for the oxygen concentrator and related electricity charges were 48,414±15,618 won/month and 40,352±36,815 won/month, respectively. Approximately 75% of patients had a regular visit by the company. 5.8% of patients had personal pulse oxymetry. 54.9% of patients had their oxygen saturation checked on each visit hospital. 8% of patients were current smokers. The most common complaint with LTOT was the limitation of daily activity (53%). The most common complaint with oxygen concentrators was noise (41%). 본연구는보건복지가족부보건의료기술진흥사업의지원에의하여이루어졌음 (A040153). Address for correspondence: Jee-Hong You, M.D. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, East-West Neo Medical Center, Kyung Hee University College of Medicine, 149, Sangil-dong, Kangdong-gu, Seoul 134-727, Korea Phone: 82-2-440-6117, Fax: 82-2-440-6295, E-mail: honglung@chollian.net Received: Jun. 14, 2009 Accepted: Jul. 8, 2009 88
Tuberculosis and Respiratory Diseases Vol. 67. No. 2, Aug. 2009 Conclusion: The patients showed good compliance with LTOT. However, only a few patients used an ambulatory oxygen device or had their oxygen saturation measured. Key Words: Long-term home oxygen therapy, Reimbursement, Chronic respiratory insufficiency, COPD 서론지속적인가정산소치료는저산소증을동반한중증만성폐쇄성폐질환 (chronic obstructive pulmonary disease, COPD) 환자의사망률을낮춘다 1,2. 이에가정산소치료는점점증가하고있으나지속적인산소공급을유지하기위한높은의료비용으로장기간산소치료가필요한 COPD 환자에게상당한경제적부담이되었다. 따라서, 국가의재정지원이필요하게되었고, 이에여러나라에서가정산소치료에대해의료비를지출하고있으며 3-7, 미국 Medicare에서는가정산소치료에대해매년 20억달러를보험급여로지출하고있다 3. 우리나라의경우만성기도질환환자중에서가정산소치료가필요한환자의 50% 정도밖에산소치료가시행되지않았고이로인하여의료정책입안자들은가정산소치료의사회적인총의료비용이낮다고판단하였다 8. 이런낮은사회적관심도로인해가정산소치료가그동안보험급여혜택을받지못하는상태였다. 그러나 2006 년 11월부터국민건강보험공단은 COPD 환자의경제적부담을경감하고건강보험의보장성을강화하기위해저산소증을보이는중증의만성심폐질환자에서호흡기내과전문의의처방에의해산소발생기로가정산소치료를받는경우보험급여를적용하여요양비를청구할수있도록국민건강보험법제44조및시행규칙에의한요양비의보험급여기준및방법을시행하였다 9. 이후 2007년 8월부터는호흡기장애인이급여대상에포함되도록하였으며, 내과전문의, 결핵과전문의및흉부외과전문의도처방할수있도록확대하였다 10. 본연구는가정산소치료의보험급여시행이후처방된가정산소치료실태를조사하고자시행하였다. 대상및방법 1. 대상환자 2006 년 11월 1일부터 2008 년 6월 30일까지만성기도폐쇄성질환임상연구센터제3세부과제만성기도폐쇄성질환진료지침개발 / 보급연구의연구자들이속한 13개대학병 원에서호흡기내과전문의로부터가정산소처방을받은환자들의의무기록지검토와설문조사를시행하였다. 2. 자료의수집대상환자들의기저질환, 가정산소치료의처방기준으로이용된검사종류 ( 동맥혈가스검사결과, 폐기능검사결과, 맥박산소측정기로측정한산소포화도, 호흡곤란의증상 ), 호흡기장애등록여부, 흡연상태, 가정산소치료전과후의산소포화도를의무기록검토를통해조사하였다. 산소흡입량, 산소전달방법, 산소공급기종류, 이동용산소공급기유무, 하루산소흡입시간, 산소발생기회사의방문횟수, 산소발생기대여료, 산소발생기사용시증가된전기요금, 가정산소치료후증상의변화 ( 호흡곤란, 급성악화, 전신부종, 수면의질 ), 가정산소치료시의불편함 ( 비용, 일상활동의제약, 두통, 산소발생기관련불편함 ) 에대해환자에게외래방문시또는전화를통해설문조사를시행하였다. 3. 자료의분석모든통계값은평균 ± 표준편차로표기하였다. 산소사용전후의변수의비교는대응표본 T검정인 paired t-test 를이용하였고, p값이 0.05 이하인경우유의한것으로판정하였다. 통계분석은 SPSS 12.0 (SPSS Inc., Chicago, IL, USA) 를이용하였다. 결과총 197명의환자가가정용산소치료처방을받았고, 이중남자가 131명 (66.5%) 이였으며, 호흡기장애등록자는 108명 (57.1%), 평균나이는 64.3±13.0세였으며 (Table 1) 70대가가장많았다 (Figure 1). 이들의평균 FEV 1 /FVC는 37.6±18.7%, FEV 1 는예측치의 52.5±20.5% 였다. 흡연력이있던환자는전체의 60.8% 였으며, 이중 7% 는흡연상태였다 (Table 1). 기저폐질환은 COPD가 52.3% 로가장많았으며, 결핵파괴폐 (19.8%), 기관지확장증 (6.6%), 간질성폐질환, 폐암, 척추후측만증의순서였다 (Table 2). 89
MJ Park et al: Long-term oxygen therapy after insurance reimbursement in Korea Table 1. Patients characteristics Characteristics Patients, n 198 Age, years 64.5±13.1 Sex M/F, n (%) 131/67 (66.5/33.5) Registered disabled person Respiratory organ, n (%) 107 (56.9) Pulmonary function test FEV 1/FVC 37.6±18.8 FEV 1, % predicted 52.6±20.5 FVC, % predicted 55.4±22.7 Smoking status, n (%) Current smokers 13 (7) Ex-smokers 100 (53.8) Non-smokers 73 (39.2) FEV 1: forced expiratory volume in one second; FVC: forced vital capacity. 호흡기내과전문의가가정산소치료를처방하기위해이용한기준으로는동맥혈가스분석결과저산소혈증을보이는경우가 64.8% 로가장많았으며, 14% 는호흡곤란의증상, 9.8% 는맥박산소측정기를이용한산소포화도의감소, 11.4% 는폐기능검사와호흡곤란의증상을산소처방의기준으로이용하였다 (Table 3). 산소공급용기는산소발생기가 98.3% 로가장많았으며, 이중임대는 89.1%, 구매는 9.1% 였고, 압축산소통은 1.7% 였다 (Table 4). 산소전달방법은 98.3% 가코삽입관을이용하였으며 1명은마스크, 2명은비침습적양압환기기를이용하였다. 이동시휴대용산소용기를사용하는환자는 33명 (19%) 이었다. 산소사용시간은 16.9±6.7 h/day였고, 하루 15시간이상산소를사용하는환자가 116명 (68.2%) 이었다. 평균산소유량은휴식시 1.6±0.7 L/min, 운동시 2.1±0.9 L/min, 수면시 1.5±0.8 L/min였다 (Table 4). 산소치료전후의 SaO 2 는각각 83.2±10.5%, 91.6±7.0% 였다 (p<0.001) (Figure 2). 산소치료후호흡곤란의호전이 82.9%, 전신부종의호전이 3.6%, 수면의질향상이 30.9%, 급성악화의감소가 6.1% 에서관찰되었다 (Figure 3). 휴대용맥박산소측정기로집에서산소포화도를측정하는환자는 10 Table 3. Bases for prescription of LTOT Bases for prescription of oxygen n (%) Figure 1. Distribution of age in the study population with long-term oxygen therapy. Arterial blood gas analysis 125 (64.8) Symptom (dyspnea) 27 (14) Pulse oxymeter (SaO 2) 19 (9.8) Pulmonary function test with symptom 22 (11.4) LTOT: long-term oxygen therapy. Table 2. Underlying disease n (%) COPD 103 (52.3) TB-destroyed lung 39 (19.8) Bronchiectasis 13 (6.6) ILD 13 (6.6) Lung caner 6 (3.0) Kyphoscoliosis 5 (2.5) Bronchial asthma 3 (1.5) Others* 14 (7.1) COPD: chronic obstructive lung disease; TB: tuberculosis; ILD: interstitial lung disease. *Sleep apnea, tuberous sclerosis, primary pulmonary hypertension, muscular dystrophy. Table 4. Delivery of oxygen n (%) Oxygen therapy devices Oxygen concentrator 170 (98.3) Purchase 16 (9.1) Rent 153 (89.1) Compressed oxygen (cylinder) 3 (1.7) Portable supply of oxygen (ambulatory) 33 (19) Daily oxygen use, h 16.5±6.8 Compliance 15 h/day, n (%) 116 (68.2) Oxygen flow, l/min 1.9±0.8 At rest 1.6±0.7 During exercise 2.1±0.9 At night 1.5±0.8 90
Tuberculosis and Respiratory Diseases Vol. 67. No. 2, Aug. 2009 명 (5.8%), 가정산소처방을받은후외래추적방문시한번이라도산소포화도를측정한환자는 95명 (54.9%) 이었으나, 이중외래를방문할때마다규칙적으로측정한환자는 24.9% 였다. 산소발생기회사의정기적인방문은 75.2% 에서이루어졌으며, 2달에한번방문이 33.5% 로가장많았다 (Table 5). 산소발생기임대비용중본인부담액은 48,414±15,618원 / 월, 추가전기요금은 40,352±36,815 원 / 월이었다 (Table 6). 가장많이임대한산소발생기종류는 159,000원 / 월 ( 본인부담액 63,000원 / 월 ) 이었다 (Figure 4). 가정산소치료시가장불편한점은일상적인활동의 제한이 38.4% 로가장많았으며, 산소발생기기관련불편함이 46명 (26.8%), 산소발생기임대비용이 24명 (14%) 이였으며, 37명 (21.5%) 은불편한점이없다고하였다 (Figure 5). 산소발생기사용시불편한문제는소음이 Table 5. Monitoring for LTOT n (%) Possession of portable oxymeter 10 (5.8) Check SaO 2 at clinics Yes 95 (54.9) A regular interval per clinic visit 43 (24.9) Intermittent 52 (30) No 78 (45.1) Home visit of staff* for a regular check-up 121 (75.2) Weekly 3 (1.9) Monthly 37 (23) Bimonthly 54 (33.5) Trimonthly 13 (8.1) Bianually 14 (8.7) LTOT: long-term oxygen therapy. *Customer service staff of oxygen generator provider. Table 6. Cost for LTOT Figure 2. Changes of SaO 2 before and after the use of LTOT Using the paired t-test, p<0.001. LTOT: long-term oxygen therapy. Cost Rental fee, won/month 48,414±15,618 Cost of electricity, won/month 40,352±36,815 LTOT: long-term oxygen therapy. Figure 3. Changes in the patients' quality of life after long-term oxygen therapy. Figure 4. Total rental fee for oxygen concentrator (reimbursement rates are 96,000 won/month). 91
MJ Park et al: Long-term oxygen therapy after insurance reimbursement in Korea Figure 5. Reported complaints with regard to long-term oxygen therapy. 41% 로가장많았다. 고 COPD는 2002년미국의 4번째사망원인질환이며 11 우리나라에서는 2006년사망원인 8위인질환이다 12. 공공의료관점에서 COPD는폐기능저하로일상생활조차어려운, 장애를유발하는중요한질환이다 7. 본연구결과에서도저산소증과호흡곤란으로인한만성폐질환중가정산소치료처방의가장많은원인질환은 COPD이었으며이는외국의보고와같았다 4. 저산소증을동반한 COPD환자에게장기산소치료는운동능력, 혈류역학, 폐역학을호전시키며궁극적으로는사망률을감소시킨다 1,2,13. Medical Research Council 1 보고에서하루 15시간이상의가정산소치료는 COPD 환자의사망률을낮추었고, Nocturnal Oxygen Therapy Trial 2 에서는하루 12시간보다하루 19시간이상의산소치료가사망률을낮추는효과를보고하였다. 이를근거로저산소증을동반한 COPD 환자에서하루 15시간이상의장기가정산소치료가권고되고있다 14,15. 지속적인가정산소치료를하기위해서는산소공급기가필요한데, 산소공급기구입과유지에따른경제적부담으로환자들은적절한산소공급을받지못하고있는실정이었다. 2007년국민건강보험공단의설문조사결과에의하면, 지속적인가정산소치료가필요한환자 728명중에서산소공급기를구입한환자는 25.6% ( 산소발생기 17.1%, 압축산소통 8.5%) 로적었으며, 51.5% 는병 ( 의 ) 원에입원시에만산소치료를받았다 8. 이렇게장기가정산소치료는국가의재정적지원이없어서전액환자의부담이되므로적절한치료가시행되지못하고있었으며, 또입원에따른 찰 의료비의증가를유발하였다. 이에국민건강보험공단은 2006년 11월 1일부터호흡기장애인및만성심폐질환자중의사에게산소치료에필요한처방전을발급받은자에대해보험적용과요양비지급을시행공고하였으며 8, 2007 년 8월 1일이를다시확대개정하여 9, 가정산소치료서비스의급여대상기준은다음과같다 9,10. (1) 중증의만성심폐질환자중 90일동안의적절한내과적치료후안정된기간동안에별도로시행한동맥혈가스검사결과가동맥혈산소분압이 55 mmhg 이하이거나, 동맥혈산소포화도가 88% 이하인경우또는, 동맥혈산소분압이 56 59 mmhg 이하이거나, 동맥혈산소포화도가 89% 인환자중적혈구증가증 ( 헤마토크리트>55%) 이있거나, 울혈성심부전을시사하는말초부종이있거나, 폐동맥고혈압이있는경우. (2) 호흡기 1급, 2급장애인으로서, 별도검사없이내과, 결핵과, 흉부외과전문의의처방을받은경우. 가정산소치료를위한산소공급기의종류로는압축산소통, 액화산소통, 산소발생기가있으며, 산소발생기가액체산소나, 압축산소에비해가격-효과면에서좀더우월한것으로보이나소음과비싼전기료가단점이다 5,6,15-17. 국내산소발생기는월간임대료에따라 12만원, 13만 5천원, 15만 9천원의 3종류가있으며, 임대료중 9만 6천원은요양비급여를청구하면국민건강보험공단에서환자에게지급하며, 나머지임대료는환자가부담한다. 기종은환자가자유롭게선택하며, 구매한경우에는요양비지급대상에서제외된다. 일반적으로가격이비쌀수록전기소모량이적고, 소음이적다 18. 가정산소치료는 COPD 환자의외래치료비용중가장많은부분을차지하고있다 7,19. 대한결핵및호흡기학회가 2007년전국 8개병원을대상으로조사한결과 ( 미출판자료 ) 에따르면 COPD 환자의입원비용과외래비용을합한총의료비용은 1기환자가 140 만원 / 년, 4기환자가 511 만원 / 년이다. 4기환자는가정산소치료가필요한경우가많으므로산소발생기를임대한다면산소발생기종류에따라적게는 144만원 / 년 (12만원/ 월 ) 에서많게는 192만원 / 년 (15만 9천원 / 월 ) 이추가로소요되며, 전기료까지합하면가정산소치료가필요한환자의의료비용부담은더욱높은것으로생각된다. 그러나, 건강보험의혜택으로가정산소치료환자의추가비용은 20% 수준으로감소하게되었다. 환자들의평균산소사용시간은보험급여시행이전에조사된국내단일기관자료와비교하면하루 14.5 시간 20 에 92
Tuberculosis and Respiratory Diseases Vol. 67. No. 2, Aug. 2009 서 16.5시간으로증가하였고, 하루 15시간이상사용하는환자는전체의 68.2% 로이는 Katsenos 등 21 의결과인 42.5% 보다높은순응도였다. 이는질병에대한인지도가높아진것도있겠지만, 보험급여실시로매월본인부담액이 9만 6천원감소한이유가가장큰것으로생각된다. 이렇게가정산소치료에대한순응도는보험급여시행이후높아졌으나, 이동시산소사용률은 19% 로낮았다. 또한맥박산소측정기로집에서산소포화도를측정하는환자도매우적었으며, 병원방문시외래에서한번이라도산소포화도를측정하는경우도 54.9% 로낮았으며, 산소발생기회사에서정기적으로방문하여산소포화도를측정하는경우도 75.2% 로적정산소화에대한모니터가모든환자에게시행되고잊지않음을알수있었다. Morrison 등 22 은저산소증이동반된 COPD 환자가적정한산소유량을처방받아흡입할때에도신체활동시에나수면시에는산소포화도가감소함을보고하였고, 가정산소치료를하는경우에는적정한산소화가이루어지는지에대해맥박산소측정기를이용한 24시간지속적인감시가필요하다고하였다. 또한이를근거로, 장기가정산소치료에도 COPD 환자의생존율이향상되지않았던 23 이유를적정산소화가하루종일유지되지않기때문인것으로추정하기도하였다. 본연구결과를보면, 휴대용산소공급기를사용하는환자가 19% 로낮아저산소혈증이악화되기쉬운이동시에산소를공급하기위한노력이필요한것으로보인다. 이렇게이동시산소공급이되지않는가장큰이유는휴대용산소통이보험급여적용을받지못함에따른비용문제인것으로보인다. 설문조사 8 에서도응답자중 17% 가휴대용산소통의보험급여가개선되어야할점이라고대답하였다. Ringbaek 등 24 은가정산소치료를받는환자들의외래추적관찰이저조하며, 특히호흡기내과전문의가아닌경우더욱심하다고하였다. 이들의보고에의하면, 가정산소치료처방이후 10개월간외래추적방문은 38.5% 에불과했으며, 외래방문시산소를흡입하면서동맥혈가스분석검사나, 맥박산소기를이용한산소포화도검사를시행한경우는 17.5% 였다. 본연구는호흡기내과전문의가호흡기내과외래에서처방한산소치료의실태에대해서만조사하였기에외래추적방문에서산소포화도를확인한비율이 54.9% 로상대적으로높았으나대부분의환자에서산소포화도를추적조사하는것이적절한산소처방을위해필요하겠다. 가정산소치료시흡연은산소흡입에의한생리학적이득을감소시키며, 화재의위험성이있어반드시금연할것을권고하고있다 15. 본연구에서는산소치료를받으면서도 7% 가흡연을하고있었다. 따라서장기산소치료를받는환자들에게더욱철저한금연교육이필요할것으로보인다. 만성질환은지속적인치료와교육이필요하므로, 의료비용에대한국가의관심과도움이절실히필요하다. 만성신부전환자도투석비용중 80% 는국가에서보험급여혜택을받고, 나머지 20% 인약 30만원 / 월을본인이부담한다 25. 그러나혈액투석환자의대부분이장애등록자또는난치성질환 26 으로국가의보조를 100% 받는것과비교해본다면, 난치성질환의대상이아닌 COPD를포함한만성폐질환환자의본인부담은결코적다고할수없겠다. 기존의조사결과를보면가정산소치료의순응도가감소하는가장흔한원인은일상활동의제약, 코삽입관의불편함이다 27. 이와비슷하게본연구에서도일상활동의제약이가장많이호소하는불편함이었으며, 산소발생기관련해서는소음이가장많았다. 본연구는보험급여실시이후국내에서처음으로보고되는가정산소치료의다기관연구결과이며특히, 현재시행되고있는가정산소치료의현황과문제점을조사, 분석하였다. 결론적으로, 가정산소치료를받고있는만성폐질환환자들의산소치료순응도는비교적좋았으나, 적정산소화가이루어지는지에대한모니터와금연교육이필요하며, 보험급여의혜택이가정산소치료의경제적부담을감소시켜더많은 COPD 환자의장기치료에어느정도기여한것으로생각된다. 참고문헌 1. Medical Research Council Working Party. Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema. Lancet 1981;1:681-6. 2. Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: a clinical trial. Nocturnal Oxygen Therapy Trial Group. Ann Intern Med 1980;93:391-8. 3. Croxton TL, Bailey WC. Long-term oxygen treatment in chronic obstructive pulmonary disease: recommendations for future research: an NHLBI workshop report. Am J Respir Crit Care Med 2006;174:373-8. 4. Jones A, Wood-Baker R, Walters EH. Domiciliary oxy- 93
MJ Park et al: Long-term oxygen therapy after insurance reimbursement in Korea gen therapy services in Tasmania: prescription, usage and impact of a specialist clinic. Med J Aust 2007; 186:632-4. 5. Borras JM, Granados A, Escarrabill J, de Lissovoy G. Complex decisions about an uncomplicated therapy: reimbursement for long-term oxygen therapy in Catalonia (Spain). Health Policy 1996;35:53-9. 6. Dilworth JP, Higgs CM, Jones PA, White RJ. Acceptability of oxygen concentrators: the patient's view. Br J Gen Pract 1990;40:415-7. 7. Pelletier-Fleury N, Lanoe JL, Fleury B, Fardeau M. The cost of treating COPD patients with long-term oxygen therapy in a French population. Chest 1996;110:411-6. 8. Department of Insurance Benefit, National Health Insurance Corporation, Korea. Report on the survey about home oxygen therapy 2007. Seoul: National Health Insurance Corporation; 2007. 9. National Health Insurance Corporation, Korea. Public bulletin No. 2006-1. Seoul: National Health Insurance Corporation, Korea; 2006. 10. Ministry for Health, Welfare and Family Affairs, Korea. Public notification No. 2007-66. Seoul: Ministry for Health, Welfare and Family Affairs, Korea; 2007. 11. Jemal A, Ward E, Hao Y, Thun M. Trends in the leading causes of death in the United States, 1970-2002. JAMA 2005;294:1255-9. 12. Korea National Statistical Office. Annual report on the cause of death statistics 2006. Daejeon: Korea National Statistical Office; 2007. 13. Tarpy SP, Celli BR. Long-term oxygen therapy. N Engl J Med 1995;333:710-4. 14. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) [Internet]. [place unknown]: GOLD; c2009. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. Available from: http://www.goldcopd.com. 15. ACCP-NHLBI National Conference on Oxygen Therapy. Chest 1984;86:234-47. 16. Lowson KV, Drummond MF, Bishop JM. Costing new services: long-term domiciliary oxygen therapy. Lancet 1981;1:1146-9. 17. Oxygen concentrators. Health Devices 1993;22:485-97. 18. Ministry for Health, Welfare and Family Affairs, Korea. Public notification No. 2006-77. Seoul: Ministry for Health, Welfare and Family Affairs, Korea; 2006. 19. Petty TL, O'Donohue WJ Jr. Further recommendations for prescribing, reimbursement, technology development, and research in long-term oxygen therapy. Summary of the Fourth Oxygen Consensus Conference, Washington, D.C., October 15-16, 1993. Am J Respir Crit Care Med 1994;150:875-7. 20. Huh JW, Lee JY, Hong SB, Oh YM, Shim TS, Lim CM, et al. Long-term oxygen therapy in patients with chronic respiratory failure in one university hospital. Tuberc Respir Dis 2005;58:160-6. 21. Katsenos S, Charisis A, Daskalopoulos G, Constantopoulos SH, Vassiliou MP. Long-term oxygen therapy in chronic obstructive pulmonary disease: the use of concentrators and liquid oxygen systems in north-western Greece. Respiration 2006;73:777-82. 22. Morrison D, Skwarski KM, MacNee W. The adequacy of oxygenation in patients with hypoxic chronic obstructive pulmonary disease treated with long-term domiciliary oxygen. Respir Med 1997;91:287-91. 23. Górecka D, Gorzelak K, Sliwińki P, Tobiasz M, Zieliński J. Effect of long-term oxygen therapy on survival in patients with chronic obstructive pulmonary disease with moderate hypoxaemia. Thorax 1997;52:674-9. 24. Ringbaek TJ, Lange P, Viskum K. Are patients on longterm oxygen therapy followed up properly? Data from the Danish Oxygen Register. J Intern Med 2001;250: 131-6. 25. Law of National Health Insurance, Korea. Article, No. 44. 26. Center for Rare disorder, Korea Centers for Disease Control and Prevention. 2008 Rare disorders which were supported for medical cost. Seoul: National Institute of Health, Korea; 2008. 27. O'Reilly P, Bailey W. Long-term continuous oxygen treatment in chronic obstructive pulmonary disease: proper use, benefits and unresolved issues. Curr Opin Pulm Med 2007;13:120-4. 94