종양간호연구 제17권제1호, 2017년 월 Asian Oncol Nurs Vol. 17 No. 1, 111 유방암환자의영양중재효과메타분석 정복례 1 오은희 2 1 경북대학교간호학과 간호과학연구소, 2 경북대학교병원 The Effect of Intervention in Breast Cancer: A Metaanalysis Chung, Bok Yae 1 Oh, Eun Hee 2 1 College of Nursing, Research Institute of Nursing Science, Kyungpook National University, Daegu; 2 Department of Nursing, Kyungpook National University Hospital, Daegu, Korea Purpose: The purpose of this study was to evaluate the effect of diet intervention in breast cancer patients through metaanalysis. Methods: For the study purpose, 18 studies were selected using PubMed, ScienceDirect, ProQuest and CINAHL. Metaanalysis was performed using a random effects model, and the effect size on outcome variables in breast cancer were calculated. Results: The effect size for body mass index, body weight, energy intake from fat (%), and energy intake of diet intervention was 0.75 (95% CI:1.22~ 0.27), 0.9 (95% CI:1.58~0.28), 0.82 (95% CI:1.11~0.52), and 1.10 (95% CI:1.85~0.4). For heterogeneity, moderator analysis was performed using intervention type and intervention duration. As a result of the moderator analysis, BMI, body weight, energy intake from fat (%), and energy intake were not statistically significant on intervention type and intervention duration. But, only BMI had a significant difference on intervention duration (p=.01). Conclusion: Further research is needed to determine whether exercise intervention will be included in nutritional intervention for breast cancer patients. Also, even if the duration of the intervention is less than six months, a strategy for sustaining longterm intervention effects will be needed. Key Words: Breast Neoplasms,, MetaAnalysis 1. 연구의필요성 서 국립암센터 1) 의통계자료에의하면유방암이여성암중 2 위를차 지하고있고, 인구 10 만명당 1999 년 24.5 명에서 201 년 52.1 명으로 연간 5.7% 씩증가하고있으나, 국가의암검진사업시행이확대되고, 개인도건강검진에대한인식이증가함에따라유방암의진단시기 가빨라져 0 기또는 1 기단계의초기유방암수준에서진단되고있 다. 이로인해유방암환자는수술과항암화학요법및방사선요법 주요어 : 유방암, 영양, 메타분석 *2015년도정부 ( 교육부 ) 의재원으로한국연구재단의지원을받아수행된기초연구사업임 (No. 2015R1D1A1A0106149). * This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(No. 2015R1D1A1A0106149). Address reprint requests to: Oh, Eun Hee Kyungpook National University Hospital, 10 Dongdeokro, Junggu, Daegu 41944, Korea. Tel: +8252005170 Fax: +8252005171 Email: misum1999@naver.com Received: Jan 10, 2017 Revised: Mar 18, 2017 Accepted: Mar 24, 2017 This is an Open Access article distributed under the terms of the Creative Commons Attribution NonCommercial License (http://creativecommons.org/licenses/bync/.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 론 을적극적으로시행할수있게되었고, 이는 5년생존률의증가로이어져유방암진단이후생존기간이 20~0년정도로길어지면서장기적인관점에서의유방암관리에대한관심이증가하고있다. 유방암환자의영양은모든유방암환자의질병극복과정에서중요하다. 이는식이및영양요법이유방암의발생과유방암의치료및예후 24) 에영향을주는것으로보고되고있기때문이다. 특히, 유방암의치료와예후에있어고지방식이를섭취하는것이사망률을높이고, ) 식이에포화지방과트랜스지방을줄이는것이생존을높일수있음을제안하고있다. 5) 또한비만이유방암의원위부전이와사망에있어유방암의예후에영향을미치며항암치료와내분비치료등의보존치료의효과도떨어뜨리는것으로보고하고있고, 6) 유방암환자의 BMI (Body Mass Index) 와생존에대한메타분석연구에서는정상체중을가진환자에비해과체중이거나비만인환자의경우유방암관련사망위험이유의하게증가하는것으로보고하고있다. 7) 이처럼유방암생존자의경우신체활동이낮고, 과체중이거나비만인생활습관이유지된다면유방암의재발과다른만성질환발생의위험요인이될수있으므로, 8) 신체활동늘리기, 체중감소, 채소와과일많이섭취하기, 지방감소식이를포함한생활습관개선이필요함을제 2017 Korean Oncology Nursing Society pissn 2287244 eissn 2287447X
2 정복례외 유방암환자의영양중재효과메타분석 안하고있다. 9) 따라서유방암의발생빈도를낮추고유방암의치료효과를높이며재발을감소시키기위한식이및영양관련중재연구가이루어지고있고, Cho 등 10) 은과일과채소를많이섭취하는것이유방암의위험을낮추는것으로보고, 식이상담과요리수업을포함한식이중재를진행하면서과일과채소섭취를늘리는식이중재를시행하여늘어나는유방암의유병률을줄이고자하였으며, Christifano 등 2) 도비만과식사의질이유방암의유병률및사망률과관련이있다고보고체중감소와식사의질개선을위한체중감소중재를시행하였고, 체중감소와식사의질이유방암생존자들의장수와삶의질에관련이있음을보고하였다. 하지만지금까지이루어진유방암환자를대상으로한영양중재연구의대부분은체중감소와건강한식이습관으로의개선을목적으로이루어지고있고 111) 식이중재와함께운동중재를병행하는연구가많았으며, 111) 중재결과체중감소, BMI 감소, 식이에서지방섭취비율감소, 총에너지섭취량감소등중재후중재의결과도다양하다. 식이중재의기간또한중재의기간을최소 12주 14) 부터시작하여 5년 15) 까지연구마다상당한차이가있었고, 중재후중재효과의유지도최대 6년 15) 까지의기간동안시도되고있었다. 중재를적용함에있어서도그룹또는개별로구분하여중재를적용하기도하지만, 그룹활동을기본으로하면서개별화된중재를병행하거나, 1) 개별상담과전화상담을병행하는 11) 등방법적인면에서도연구마다차이를보이고있었다. 식이중재방법은영양사를통한설명및상담이많이이루어졌고, 주요교육내용으로는에너지섭취비율감소, 지방섭취비율감소, 음식에대한정보제공, 라벨링확인등전반적인영양에대한교육이포함되고있었다. 11,16) 유방암영양중재관련체계적고찰이나메타분석연구를보면 Hauner 등 17) 은유방암환자의예후에과체중과식이가미치는효과에대한메타분석연구에서유방암진단시 BMI가높은것이나중에체중이증가하는것만큼이나전반적인사망률을더높이는것과관련이있음을보고하면서, 아직까지중재연구가부정적인효과를보이고있지만, 과체중을피하고, 과일, 채소및섬유소가풍부하고지방이적은식이를섭취하는것을권고하고있었다. Playdon 등 18) 은유방암진단후체중증가에대한체계적고찰과메타분석연구를통해유방암진단전 BMI가높거나낮은것은통계적으로유의하지않았지만, 유방암진단후체중이증가하는것은체중을유지하는것과비교할때사망률이더높이는것과관련이있음을보고하고있다. 또한 Spark 등 19) 은신체활동과영양에대한중재를적용하고, 그지속효과도연구들이보고있는지에대한체계적고찰을하였고, 그결과대부분의연구들이지속효과에대해서는조사하고있지않아장기간의건강관련결과를개선시키기위 한중재를개발하는데관심을가져야함을제안하고있었다. 이상의연구에서보듯이유방암환자의경우다른여러암에비해영양중재의중요성이많이보고되고있고, 이에따라영양중재연구가지속적으로이루어지고있으며, 영양중재의경우체중과 BMI 감소를주로목표로하고있었으며, 영양적인칼로리부분에대한효과를동시에보고있었다. 그러나영양중재를적용함에있어운동중재를포함하는경우도있고, 포함하지않는경우도있으며, 영양중재의유형이나중재의기간등도다양하게보고되고있어다양한영양중재방법들간의효과비교가필요함을알수있으나, 이에대한연구는부족한실정이다. 이에본연구에서는유방암환자에게적용한다양한영양중재연구를메타분석을이용하여기존중재프로그램의타당성과 BMI, 체중감소등에대한효과를파악함으로써향후유방암환자를대상으로한영양중재시효과적인중재방법및중재기간에대한학문적기초자료를제시하고자한다. 2. 연구목적본연구는유방암환자를대상으로한영양중재연구를메타분석하여영양중재프로그램의효과를검증함으로써근거에기반된효과적인영양중재프로그램을개발하기위한기초자료를제시하기위한것으로구체적인연구목적은다음과같다. 첫째, 문헌고찰을통하여선별된연구의일반적특성을파악한다. 둘째, 메타분석에포함된연구를중심으로영양중재의효과크기를산출한다. 셋째, 산출된효과크기의이질성을확인하고그에따른조절효과를분석한다. 연구방법 1. 연구설계본연구는유방암환자를대상으로시행한영양중재프로그램에대한국외연구결과의효과크기를통계적으로통합하기위해수행된메타분석이다. 2. 연구대상및선정기준본연구는 Cochrane collaboration 20) 과 PRISMA 21) 의체계적문헌고찰에따라진행되었다. 연구의대상및선정기준을체계적고찰의일반적기술형식인 PICOS (Participants, Intervention, Comparison, Outcomes, Study design) 에따라서술하면다음과같다. 본연구의대상 (P) 은유방암환자이나, 발생기전과치료가유사한전립선
정복례외 유방암환자의영양중재효과메타분석 암환자가일부포함된연구는연구대상에포함하였다. 중재방법 (I) 은영양중재프로그램으로서, 모든유형의영양중재방법을포함하였으나, 단일식품이나단일성분만을대상으로한연구는제외하였다. 대조군 (C) 은중재프로그램을실시하지않는군이다. 결과 (O) 는중재프로그램의효과로서, 체중, BMI, 에너지섭취비율및섭취량등을포함하고있다. 연구유형 (S) 은실험군 대조군사전사후설계의실험연구를대상으로하였고, 대조군이없거나단일군사전사후실험연구는제외하였다. 문헌검색은 2016년 7월부터 10 월사이에이루어졌고, 2000년부터 2016 년까지국외학술지에발표된영어로발표된국외논문으로다음과같은기준에의해연구자 2 인이검색된문헌을기준에따라선정하였다 (Fig. 1). 첫째, 검색어는핵심질문의구성요소로부터주요검색어를도출하였으며, breast cancer AND/OR neoplasm, nutrition AND/OR diet 및 Intervention, Body weight, BMI 및 Energy intake 를검색어로국외데이터베이스 PubMed, Science Direct, ProQuest 및 CINAHL을활용하여총 9,49 편의문헌을수집하였다. 둘째, 중복게재된논문 664편은제외하고, 8,775편을선정하였다. 셋째, 제목과초록을검토하여대상자선정기준에부합하는연구 65편을선정하였다. 이중에서비실험연구, 단일군유사실험연구등 편은제외하였다. 넷째, 메타분석에필요한효과크기를계산하는데필요한통계치 ( 평균, 표준편차. 사례수, p) 가정확히제시되지않은논문 14편을제외하여최종 18편의논문이선정되었다.. 자료코딩과분석기준총 18편의연구논문을분석하여연구자 2인이코드화하여정리하였다. 코딩자료는일련번호, 저자, 발표연도, 연구설계, 표본수 ( 실험군, 대조군, 전체 ), 중재종류, 중재기간, 결과등으로구성하였다. 또한효과크기산출을위하여평균, 표준편차, 표본의크기는별도로취합하였다. 코딩시신뢰도를유지하기위해연구원 2인이따로실시하고누락및오류발견시재확인을통해서수정하였으며, 최종자료가불일치하는항목이없어코딩자간신뢰도, 타당도는시행하지않았다. 4. 자료분석 1) 연구대상의방법론적질평가연구의대상은무작위대조군연구 15편과비무작위대조군연구 편이었다. 무작위대조군연구의질평가는 Cochrane ROB (risk of bias) 를사용하였다. Cochrane ROB는무작위배정순서생성, 연구참여자ㆍ연구자에대한눈가림, 결과평가에대한눈가림, 불충분한결과자료, 선택적보고, 그외삐뚤림 7문항으로구성되었으며, 각문항에대한평가결과는낮음, 높음, 불명확으로나타내었다. 비무작위대조군연구는한국보건의료연구원의 RoBANS (risk of bias assessment tool for nonrandomized study) 를사용하였다. 22) RoBANS는대상군선정, 교란변수, 노출측정, 결과평가, 불완전한결과자료, 선택적결과보고의 6문항으로구성되어있으며, 각문항에대한평가결과는낮음, 높음, 불명확으로나타내었다. 평가도 Fig 1. Flow chart of study selection process.
4 정복례외 유방암환자의영양중재효과메타분석 구를바탕으로연구자 2 인이각각문헌의질평가를수행하였으며, 이를함께검토하여일치된평가결과가나오도록진행하였다. 재기간은 개월 2 편, 4 개월 편, 6 개월 5 편, 10 개월 2 편, 1 년 4 편, 2 년 1 편, 5 년 1 편이었다. 2) 효과크기 (effect size) 의산출총 18편의연구논문을대상으로 Comprehensive MetaAnalysis version..1을활용하여영양중재를받은유방암환자에대한효과크기를산출하였다. 효과크기 (summary effect) 는각연구의연구방법, 표본, 중재방법이다양한점을인정하여임의효과모형 (random effect model) 을적용하여산출하였다. 그리고종속변수를측정하는도구가다른경우를비교하기위하여표준화평균차이 (standardized mean differences, SMDs) 를산출하는데, Cohen s d는표본이작을경우효과크기를과대추정하는경향이있으므로교정된표준화된평균효과크기 (corrected standardized mean difference) 즉 Hedges g 를효과크기로산출하였으며 95% 신뢰구간 (Confidence Intervals,CI) 으로계산하였다. 2) 연구의동질성여부는 Q통계량과아이제곱검정 (I) 으로확인하였다. 일반적으로 Q값에대한유의확률이 0.10 이하이고, I가 50% 를넘으면그이질성의정도는상당하다고해석할수있어, 17) I가 50% 를넘는연구들의경우효과크기의이질성에대해서는조절변수의속성에따라메타 ANOVA를활용하여조절효과분석을실시하였다. 마지막으로 Funnel plot을사용하여출간오류 (publication bias) 를분석하였고, 삼각형모양의기준선을중심으로대칭적으로분포되어있으면출간오류가발생하지않은것으로해석하였다. 연구결과 1. 연구의일반적특징 2000년이후국외유방암환자의영양중재효과분석을위해최종선정된연구논문 18편에대한일반적특성은 Table 1과같다. 연구방법은 Randomized Controlled Trials (RCT) 15편, NonRandomized Controlled Trials (NRCT) 편이었다. 대상자의경우유방암을진단받고치료중인대상자를대상으로한연구가 5편, 생존자를대상으로한연구가 1편이었다. 유방암의병기를보면, 병기에대한정확한기술이없는연구가 5편, stage 0~II 환자를대상으로한연구 1편, early stage 환자를대상으로한연구가 5편, stage 0~III 환자를대상으로한연구가 7편이었다. 연구대상자의평균연령을보면 40대인연구가 1편, 50대인연구가 8편, 60대인연구가 4편, 70대인연구가 1편, 20~65세사이 1편, 연령에대한기술이없는연구가 편이었다. 중재의유형은연구에서는다양한이름으로프로그램을설명하고있지만, 크게구분하여영양중재만을시행한연구는 10 편이었고, 운동을포함한영양중재를시행한연구는 8편이었다. 중 2. 연구의질평가결과연구논문 18편중무작위대조군연구 15편에대해서는 Cochrane ROB를사용하여평가한결과무작위배정순서에서비뚤림위험이낮은연구가 7편, 무작위배정순서에대한기술이명확하지않아불확실한연구가 5편이었고, 검사결과나의사처방에의한배정등순서생성시부적할방법으로배정한 편은비뚤림위험이높은것으로평가하였다. 배정순서의은폐와참가, 연구자눈가림은낮음이 6편, 불확실한연구가 9편이었고, 결과평가에대한눈가림은낮음이 8편, 기술이명확하지않아불확실한연구가 7편이었다. 탈락비뚤림, 선택적보고및그외비뚤림위험문제는 15편모두비뚤림위험이낮은것으로평가하였다. 비무작위대조군연구 편에대해 RoBANS를사용하여평가한결과대상군선정, 노출측정, 불완전한결과자료및선택적결과보고에서는 편모두비뚤림이낮은것으로평가하였으며, 교란변수, 결과평가에대한눈가림에있어서는 편모두이에대한기술이없어불확실한것으로평가하였다 (Table 2).. 유방암환자에게적용한영양중재효과크기논문 18편을대상으로집단의평균, 표준편차, 표본크기를이용하여교정된표준화된평균차이 (Hedges g) 를산출한결과를 forest plot으로제시하였다 (Fig. 2). 영양중재의효과를검증하기위한결과변수를중심으로연구들의평균효과크기를검증하였다. BMI에대한평균과표준편차가제시된 12편의논문들을대상으로본 BMI의평균효과크기 Hedges g = 0.75 (95% CI: 1.22~0.27) 로나타났고, 전체크기의이질성은총분산에서연구간분산이차지하는비율 I = 94.5% (Q = 201.0, p<.001) 로이질성이높았다. Body Weight에대한평균과표준편차가제시된 9편의논문들을대상으로본 Body Weight의평균효과크기 Hedges g = 0.9 (95% CI: 1.58~ 0.28) 으로나타났고, 전체크기의이질성은총분산에서연구간분산이차지하는비율 I = 9.2% (Q =117.42, p<.001) 로이질성이높았다. Energy Intake from fat (%) 에대한평균과표준편차가제시된 11편의논문들을대상으로본 Energy Intake from fat (%) 의평균효과크기 Hedges g= 0.82 (95% CI: 1.11~0.52) 로나타났고, 전체크기의이질성은총분산에서연구간분산이차지하는비율 I =90.0% (Q = 99.98, p<.001) 로이질성이높았다. Energy Intake에대한평균과표준편차가제시된 9편의논문들을대상으로본 Energy Intake의평균효과크기 Hedges g = 1.10 (95% CI: 1.85~0.4) 으로나타났고, 전
정복례외 유방암환자의영양중재효과메타분석 5 Table 1. General Characteristics of Studies Included in Metaanalysis Reference Christy et al. (2011) Denmark Wahnefried et al. (2006) Denmark Wahnefried et al. (2007) Denmark Wahnefried et al. (2008) Denmark Wahnefried et al. (2014) Djuric et al. (2002) Goodwin et al. (2014) Greenlee et al. (2015) Harrigan et al. (2016) Hebert et al. (2001) Hoy et al. (2009) Mefferd et al. (2007) Pakiz et al. (2011) Schiavon et al. (2015) Shaw et al. (2007)a Shaw et al. (2007)b Thompson et al. (2015) Winters et al. (2004) Study design Staging Subject Sample size Intervention Exp. Cont. T type RCT Early stage Intervention duration Measurement PC, BC 26 25 489 10 months quality index, Total % calories from fat, Total % calories from saturated fat, No. of daily servings of F/V, BMI RCT BC, PC 77 8 160 Exercise+ RCT Early stage BC, PC 25 266 519 Exercise+ RCT IIIIA BC CA+EX 26 CA+EX+ FVLF29 RCT 0~III Overweight Individual 2 BC & Daughters Team 2 RCT BC WW 6 IC 9 Combination 8 CA 27 82 Exercise+ 17 6 Exercise+ 6 months Exercise frequency, selfefficacy, readiness to exercise, energy intake from fat (%), fruit and vegetable intake, BMI, depression 10 months BMI, dietary consumption, physical activity, psychosocial/behavioral indices 6 months Physical activity, dietary intake, body composition, anthropometric, quality of life 1 year BMI, BW, SBP, physical activity, diet quality index, selfefficacy, physical quality of life, mental quality of life 11 4 1 year Weight loss, numbers of women achieving 10% weight loss, Reported dietary intakes from day food records RCT IIII BC 120 124 244 Exercise+ 2 years BW, PA,, QoL RCT 0~III BC 0 1 61 months Daily total caloric intake, daily fruit and vegetable intake, daily intake of targeted fruit and vegetable, daily fat intake, waist & hip circumference, BMI, BW RCT 0~III BC Inperson counseling Telephone counseling 4 usual care RCT I~II BC Nutrition education 50 Stress reduction 51 RCT Early stage Usual care 56 100 Exercise+ 6 months Body composition, physical activity, diet, and serum biomarkers. 157 4 months ary fat, complex carbohydrates, fiber, body mass BC 80 648 1,028 5 years Energy intake from fat (%) I~IIIA overweight BC 47 29 76 Exercise+ RCT I~IIIA overweight or obese BC NRCT Early stage 44 24 68 Exercise+ 4 months Waist & hip circumference, waistohip ratio, BMI 4 months BMI, BW, waist circumference, % body fat, PA BC 18 75 9 1 year Daily dietary intake, biomarkers, BW, BMI RCT BC Weight reduction 19 Low fat 17 15 51 6 months Arm volume, anthropometric measures, dietary intake RCT BC 11 10 21 months Arm volume, anthropometric measures, dietary intake NRCT BC Low carbohydrate diet 66 Low fat diet 7 RCT Early stage 5 192 6 months BW, BMI, body fat, body mass index, waist & hip circumference, lean weight BC 50 11 16 1 year Energy, dietary variables Exp.= Experimental group; Cont.= Control group; T= Total; RCT= Randomized Controlled Trial; NRCT= NonRandomized Controlled Trial; BC= Breast cance; PC= Prostatic cancer; BMI= Body mass index; TG= Plasma triglycerides; Chol= Plasma cholesterol; HDL= HDL cholesterol; LDL= LDL cholesterol; QOL= Quality of life; PA= Physical activity; CA= Calciumrich diet; EX= Exercise; FVLF= High fruit and vegetable and lowfat diet; WW= Weight Watchers; IC= Individualized counseling.
6 정복례외 유방암환자의영양중재효과메타분석 Table 2. Risk of Bias for RCT and NRCT Categories Domain Risk of Bias Unclear Low High Randomized controlled trial studies Random sequence generation Allocation concealment Blinding of participants and personnel Blinding of outcome assessment Incomplete outcome data Selective reporting Other bias 5 9 9 7 7 6 6 8 15 15 15 Non randomized controlled trial studies Selection of participants Confounding variables Measurement of exposure Blinding of the outcome assessments Incomplete outcome data Selective outcome reporting (reporting bias) RCT= Randomized controlled trial; NRCT= Nonrandomized controlled trial. Fig 21. Body mass index. Fig 22. Body weight.
정복례외 유방암환자의영양중재효과메타분석 7 Fig 2. Energy intake from fat (%). Fig 24. Energy intake. Fig 2. Effect Size of Outcome Variables. 체크기의이질성은총분산에서연구간분산이차지하는비율 I= 9.1% (Q =116.58, p<.001) 로이질성이높았다. 4. 조절효과분석본연구에서결과변수들의전체이질성 I이 90.0% 이상으로나타나효과크기의이질성에대한탐색적설명이필요하다고판단되어연구변수인중재유형과중재기간을조절변수 (moderators) 로하여메타 ANOVA를실시하였다 (Table ). 중재유형에따른결과변수들의효과크기를분석한결과중재의종류는크게영양중재만시행한경우와영양과운동을병행한중재 2가지로나타났다. BMI, Body Weight, Energy Intake from fat (%) 및 Energy Intake 모두영양중재만시행한군에서효과크기 Hedges g 가각각 1.04, 1.28, 1.0 및 1.40으로더큰것으로나타났으나통계적으로유의하지는않았다. 또한중재기간은 6개월을중심으로두군으로나누어분석한결과, BMI, Body Weight 및 Energy Intake는중재기간을 6개월이하로시행한군에서효과크기 Hedges g 가각각 1.16, 1.16 및 1.48로더큰것으로나타났으며, BMI는통계적으로유의하였으나, Body Weight 와 Energy Intake는통계적으로유의하지않았다. Energy Intake from fat (%) 는중재기간이 6개월을초과한군의효과크기 Hedges g 가 0.88로 6개월이하군의 Hedges g.77보다큰것으로나타났으나통계적으로는유의하지않았다. 5. 출간오류분석연구분석결과의타당성을확보하기위해출간오류분석 (publication bias analysis) 을실시하였다. 오류가존재하는지확인하는방법중하나인 funnel plot을통해서출판편향존재여부를확인하였다. 24) Funnel plot은대칭축을기준으로좌우대칭을이루면출판편
8 정복례외 유방암환자의영양중재효과메타분석 Table. Subgroup Analysis by Intervention Type and Intervention Duration Variables Categories Subgroup k Hedges g Lower 95%CI Upper I 2 (%) Qb (p) Intervention type Body mass index with exercise 6 6 1.04 0.48 1.8 1.26 0.24 0.29 97.0 8.5 0.95 (.1) Body weight with exercise 4 5 1.28 0.66 2.15 1.42 0.41 0.09 91.6 89.7 1.10 (.294) Energy intake from fat (%) with exercise 7 4 1.0 0.49 1.41 0.97 0.64 0.01 91.0 78.6 2.92 (.087) Energy intake with exercise 7 2 1.40 0.21 2.2 1.88 0.47 1.47 94.7 27.0 1.48 (.224) Intervention duration Body mass index >6 months 6 months 4 8 0.01 1.16 0.7 1.70 0.75 0.61 0.0 95.0 6.19 (.01) Body weight >6 months 6 months 2 7 0.16 1.16 1.46 1.87 1.14 0.44 0.0 92.1 1.72 (.189) Energy intake from fat (%) >6 months 6 months 5 6 0.88 0.77 1. 1.19 0.44 0.4 94. 82.8 0.14 (.705) Energy intake >6 months 6 months 4 5 0.71 1.48 1.96 2.61 0.5 0.4 8.0 96.4 0.79 (.74) 향이없는것으로해석한다. 한쪽으로치우친경우나평균에서누락된경우출간오류를검증하는 Trimandfill 방법을활용하여다시분석하였다. 25) BMI는평균의왼쪽방향으로 개의연구가치우쳐있어 Trimandfill 방법을활용하여다시분석한결과, 오른쪽으로 2개가채워졌다. 보정된 (adjusted) 효과크기는 0.28로나타나평균효과크기 0.75보다감소된것을알수있지만보정된효과크기의 95% CI가 0.88~0.29로통계적으로유의하여연구결과에영향을줄수있는오류는아니라고해석할수있다. Body weight는평균의왼쪽방향으로 개의연구가치우쳐있어 Trimandfill 방법을활용하여다시분석한결과, 추가적으로채워진것이없어효과크기는 0.9으로동일하고, 효과크기의 95% CI 가 1.58~0.28 로통계적으로유의하여연구결과에영향을줄수있는오류는아니라고해석할수있다. Energy Intake from fat (%) 는왼쪽방향으로 1개의연구가치우쳐있어 Trimandfill 방법을활용하여다시분석한결과, 오른쪽방향으로 개가채워졌다. 보정된효과크기는 0.60으로평균효과크기 0.82보다감소된것을알수있지만보정된효과크기의 95% CI가 0.90~0.1로통계적으로유의하여연구결과에영향을줄수있는오류는아니라고해석할수있다. Energy Intake는왼쪽방향으로 1개의연구가치우쳐있어 Trimandfill 방법을활용하여다시분석한결과, 오른쪽방향으로 2개가채워졌다. 보정된효과크기는 0.6으로평균효과크기 1.10보다증 가된것을알수있지만, 보정된효과크기의 95% CI가 1.26~0.54 로통계적으로유의하여연구결과에영향을줄수있는오류는아니라고해석할수있다. 논의본연구는유방암환자를대상으로한영양중재의기초자료를마련하고자, 국외유방암환자를대상으로시행한영양중재를파악하고, 유방암환자에게어느정도의효과가있었는지효과크기를확인하기위해실시되었다. 이를위해 2000년이후발표된총 9,49편의국외연구중 18편이선정되어최종분석하였다. 연구중결과변수가상이하거나비실험연구, 대조군이없는연구등은제외하였다. 연구설계는총 18편중무작위대조군연구가비무작위대조군연구보다상대적으로많았다. 메타분석에사용된무작위대조군연구의질평가결과를보면무작위순서배정에대한기술이명확하지않거나불확실한연구와검사결과나의사처방에의해배정하는등연구의질이낮거나명확하지않은연구가더많았고, 배정순서의은폐와참가, 연구자눈가림도비뚤림이높은연구가더많았다. 비무작위대조군연구의경우에도교란변수, 결과평가에대한눈가림에대해서는기술이없어연구의질에있어서도그리높지않은연구들이많아연구결과에대한해석에신중함을기할필요가있다.
정복례외 유방암환자의영양중재효과메타분석 9 대부분의영양중재연구는유방암환자전체를대상으로하고있지만, 일부는과체중또는비만인유방암환자를대상으로이루어지고있었다. 그러나연구결과를보면영양중재후중재군이대조군보다는 BMI와체중이낮은것으로보고되지만, 두군모두에서중재후에도많은환자들은 BMI가 25 이상, 체중은 70 Kg 이상으로나타나고있어과체중또는비만의상태가지속됨을알수있었다. 따라서영양중재를시행함에있어 6개월이하로단기간적용하는것이효과적이나, 장기간효과를지속시키기위한전략마련이필요함을알수있었다. 또한연구들중에는영양중재를적용할때운동중재를병행하고있는경우도있었으나, 16,2627) 본연구결과를보면 BMI, Body Weight, Energy Intake from fat (%) 및 Energy Intake 모두영양중재만시행한군에서효과크기가더큰것으로나타났으나통계적으로유의하지는않았다. 또한개별연구의질을중심으로볼때연구의질이높게평가된운동중재를병행한연구들에서도 BMI, Body Weight 및 Energy Intake from fat (%) 은중재전에비해중재후의효과차이가통계적으로유의하지않은결과가일부포함되어있었다. 따라서향후중재유형을선정할때영양중재에운동중재를병행할지에대해서는추후연구가더필요할것이라사료된다. 중재기간은연구마다상당한차이를보이고있어, 본연구에서는 6개월을중심으로단기연구와장기연구의두군으로나누어분석해보았다. 그결과 BMI는중재기간을 6개월이하의단기간으로시행한군에서통계적으로유의하게효과크기가더크게나타났다. 그러나 Body Weight와 Energy Intake는중재기간을 6개월이하의단기간으로시행한군에서효과크기가더큰것으로나타났으나, 통계적으로유의하지않았고, Energy Intake from fat (%) 는중재기간이 6개월을초과하여장기간시행한군의효과크기가 6개월이하의단기간으로시행한군보다효과크기가더큰것으로나타났으나역시통계적으로유의하지않았다. 이상의결과와같이영양중재의결과변수에따라중재기간이미치는영향이상이함을알수있다. 또한영양중재후에도환자들의체중이나 BMI는여전히과체중또는비만의상태로높게보고되고있어, 중재효과를지속시킬수있는추가적인전략마련이필요할것으로사료된다. 또한영양중재의효과를보기위한결과변수는연구마다차이가많았다. 몸무게 14,16,2628) 와 BMI 14,16,27,28) 를결과변수로많이사용하고있었으나, 전반적인섭취열량을보거나, 14,27,28) 섭취의종류와칼로리및전체에서의비율을보는연구 15,26,28) 도있었으며, 질병의예후적인측면 10) 을보는연구도있었다. 이처럼결과변수가상이하여결과값간의비교에는다소한계가있었지만전반적인효과크기는 Hedges g 로보면 0.75~1.10으로큰효과크기를보이고있었으며, 특히통계적으로도유의한차이를보인 BMI는영양중재를통해효 과적으로낮출수있음이입증되었다. 본연구결과에서보듯이유방암환자대상영양중재는체중과 BMI 를감소시키고, 식이습관을개선하는데효과가있는것으로 드러났다. 그러나본연구에서분석한논문은영양중재를통해체 중을유지하고식이습관을개선시키는것이유방암으로인한사 망률이나재발률등질병의예후측면에어떤효과가있는지에대 해서는거의다루고있지않았다. 또한현재까지국내에서도유방 암환자를대상으로전반적인영양상태를사정하고, 식이를개선 함으로써체중과 BMI 를감소시키고, 유방암의예후를개선시키고 자시도된연구가거의전무한실정이다. 따라서이상의연구결과 를바탕으로유방암환자의영양중재시중재프로그램의기초자 료가마련될수있을것이라사료된다. 그러나본연구에서분석된연구들의특성을좀더살펴보면연 구대상에있어서도일부전립선암환자가포함되어있다. 전립선암 의경우유방암과같이성 (sex) 호르몬에자극을받는대표적종양 으로발생기전과치료가유사하여본연구대상중일부전립선암 환자가포함되어있어이질성의한요소로작용했을것이라사료된 다. 질병의병기에있어서도대부분이 Early stage 의환자를대상으로 하고있으나일부는 Stage III 의환자도포함되어있으며, 유방암을 진단받고치료중인대상자를중심으로한연구도있고, 치료가종 료된생존자를중심으로한연구도있었다. 또한영양중재에있어 서도영양사와의상담을기본적으로병행하면서, 인지행동이론이 나사회인지이론과이론적인부분을근거로상담을진행된연구도 일부있었다. 이런여러이유로인해연구들간의이질성이높은것 으로나타나연구결과를중심으로결론을도출하는데신중할필 요가있을것이라사료된다. 이상의연구결과를바탕으로향후유방암환자를대상으로영 양중재를시행할경우필요한경우에제한적으로운동중재를병 행하고, 중재를적용하는시기를 6 개월이하로하더라도, 장기간중 재효과를지속시키기위한전략을마련하고, 추가적인추적조사 를지속함으로써효과가지속되는지에대해서도모니터링해볼필 요가있음을제안하는바이다. REFERENCES 1. National Cancer Center (KR). Cancer facts & figures 2016 in the Republic of Korea [Internet]. Available from: http://www.cancer.go.kr/ mbs/cancer/jsp/album/gallery.jsp?boardtype=02&boardid=1817&li sttype=02&mcategoryid=&id=cancer_050207000000&addcancerti tle [Accessed January 20, 2017]. 2. Christifano DN, Fazzino TL, Sullivan DK, Befort CA. quality of
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