와파린 복용환자의 Medication Adherence 실태 및 영향요인

Abstract

[한글]

와파린은 약물 및 음식 상호작용이 크고 좁은 치료범위를 가지기 때문에 다른 약에 비해 Medication Adherence가 더욱 중요하다. 와파린의 Medication Adherence를 높이기 위해서는 먼저 Medication Adherence의 실태를 분석하고 그 영향요인을 파악해야한다. 이에 본 연구에서는 와파린 복용환자의 Medication Adherence(이하 M.A로 표현한다.) 실태 및 영향요인을 규명하고 INR과의 관계를 파악하기 위해 시도 되었다.연구대상은 서울시 소재 Y대학 부속병원 심장혈관센터 외래를 방문한 와파린 복용환자로 2007년 4월 9일에서 2007년 4월30일까지 설문지에 응답 가능한 230명을 임의 표출하여 1년 이내에 입원경험이 있거나 복용기간이 6개월 미만인 대상자는 제외하여 최종 204명을 선정하였다.Medication Adherence 실태 및 영향요인은 설문지를 사용하였고, INR결과와 영향요인 중 일부는 의무기록을 통해 조사하였다. 수집된 자료는 SAS 8.2 Version을 이용하여 통계 처리하였으며 연구결과는 다음과 같다.1. 대상자의 와파린 관련 약물지식은 10점 만점에 평균 6.73(±1.81)점이었고, 그 중 INR과 관련된 2가지 항목에서는 25.98%와 15.69%의 정답률로 다른 항목에 비해 상대적으로 낮았다. 자기효능감은 30점 만점에 평균 25.92(±3.14)로 측정되었다. 그 중 비타민 K가 함유된 음식을 일정하게 복용할 자신이 있느냐는 질문은 3점 만점에 평균 1.91(±0.86)로 10개 항목 중에서 제일 낮았다.2. INR분석 결과 1년간 총 측정건수는 961건이었고, 그 중 치료범위에 속한 비율은 324건으로 33.71%, 치료범위 아래로 벗어난 비율은 504건으로 52.45%, 치료범위 위로 벗어난 비율은 133건으로 13.84%였다. 또한 개개인의 적정INR비율의 평균을 구하였을 때, 1년간 측정한 INR이 모두 치료범위에 들었을 경우 100%로 본다면, 적정INR비율의 평균은 43.80%(±20.43)였다. 같은 방법으로 벗어난 INR비율의 평균을 구하였을 때, 치료범위 아래로 벗어난 비율의 평균은 59.80%(±25.70)였고, 치료범위 위로 벗어난 비율의 평균은 30.80%(±16.41)로 치료범위 아래로 벗어난 비율이 높았다.3. 와파린의 M.A를 횟수, 용량, 시간, 주의사항 준수로 보았을 때 M.A의 비율은 204명중 56명으로 27.45%였고, non Medication Adherence(이하 non M.A로 표현한다)는 148명으로 72.55%였다. 그 중 주의사항을 제외한 횟수, 용량, 시간준수를 M.A로 보았을 때는 M.A가 46.57%였고, non M.A는 53.43%였다.4. M.A의 영향요인을 살펴보면 대상자의 성별, 연령, 결혼, 취업, 경제상태, 교육수준, 가족과 동거유무 등 일반적 특성과 질환의 종류, 복용기간, 약의 용량, 동반질환의 수, 평균방문횟수, 부작용, 정보유무 등 질환 및 약물관련 특성은 M.A에 영향을 주지 않았다. 반면 약물관련 지식은 M.A에 영향을 주었으며, non M.A군과 비교 시 M.A군에서 약물관련 지식점수가 높았다(P=0.023). 또한 판막수술대상자에서 집단교육이 지식에 미치는 영향을 살펴보았을 때 집단교육을 받은 군이 받지 않은 군보다 지식점수가 높게 나타났다(P=0.000). 대상자의 자기효능감은 M.A에 가장 큰 영향을 주었으며, non M.A군과 비교 시 M.A군에서 자기효능감이 높게 나타났다(P=0.000).5. M.A와 INR의 연관성을 살펴보면 심방세동환자 군에서는 M.A가 INR에 영향을 주지 않았으며, 판막수술환자 경우 INR이 치료범위보다 높은 군에서 M.A가 INR에 영향을 주었다(P=0.037).본 연구는 와파린 복용환자의 M.A의 영향요인을 일반적 특성, 질환 및 약물관련요인, 약물지식, 자기효능감의 다각도 측면에서 분석을 시도하였다. 그 결과 약물지식과 자기효능감이 M.A그룹에서 높게 나타났다. 이 연구를 바탕으로 와파린의 M.A의 영향요인인 약물지식과 자기효능감을 높이기 위한 프로그램 개발을 제언한다.

[영문]Because warfarin interacts sensitively with other medication and food, and has a narrow treatment range, medication adherence (hereinafter referred to as MA) for warfarin is more important than for many other drugs. In order to improve warfarin's MA, the actual conditions of MA need to be analyzed and the factors that affect MA discovered. Accordingly, this paper aims to describe the actual conditions of MA for the patients taking warfarin and its factors, and discover its relationship with INR.Patients taking warfarin who had visited the outpatient ward of the Cardiovascular Center, affiliated with Y University located in Seoul, from April9 to 30, 2007, were selected as research subjects, and a selective sampling of 230 patients who could respond to the survey was carried out. Of those, subjects who had been hospitalized within one year period or taken the drug for less than six months were excluded, and a total of 204 responses were ultimately used.For examining the actual conditions of MA and its factors, a survey was used, and INR results and factors influencing MA were partially examined through medical records. The collected data were statistically analyzed using SAS 8.2 Version, and the results are as follows.First, the subjects' medicinal knowledge regarding warfarin averaged 6.73(1.81) out of a perfect score of 10, and in two of the items regarding INR, the percentage of correct answers were 25.98% and 15.69%, which were low in comparison to other items. Self-efficacy measured an average of 25.92(3.14) out of a perfect score of 30. Among those items, the question, "Are you confident about regularly consuming food that contains vitamin K?" had an average response of 1.91(0.86)out of a perfect score of 3, which was the lowest score among the ten itemsSecond, the results of INR analysis showed that the number of total measurements in one year was 961, and among them, measurements that stayed within treatment range numbered 324, or 33.71% of the total, while those that measured below the treatment range numbered 504, or 52.45%, and those that measured went over the treatment range numbered 133, or 13.84%. In addition, when the average of the appropriate INR for each individual was obtained, if all the measured INR for one year was assumed to be within the treatment range and viewed as 100%, then the average of the appropriate INR was 43.80% (20.43). When the out-of-range INR average was obtained using the same method, the average of the ratio that measured below the treatment range was 59.80% (25.70), and the average of the ratio that measured above the treatment range was 30.80% (16.41), thus marking the below treatment range ratio higher than the above ratio.Third, when MA was viewed in terms of observing frequency, dosage, time, and instructions, the ratio of MA was 56 people among 204, or 27.45%, and non-medication adherence (hereinafter referred to as non-MA) was 148, or 72.55%. Among these factors, when MA was viewed only in terms of observing frequency, dosage, and time, excluding instructions, the ratio of MA was 46.57% and non-MA was 53.43%.Fourth, when factors that affected MA were examined, general characteristics such as subject's gender, age, marital status, occupation, economic status, educational level, and whether or not the subject lived with his or her family, as well as disease and drug related characteristics such as disease type, medication period, drug dosage, number of accompanying diseases, average number of visitations, side-effects, and whether or not there was information none of these factors affected MA. On the other hand, knowledge pertaining to medication influenced MA, and when compared to the non-MA group, the MA group's knowledge pertaining to medication was higher (P=0.023). In addition, when the effect of group education on knowledge was examined in valve surgery subjects, the group that received group education showed a higher knowledge score than the group that did not (P=0.000). The subject's self-efficacy exerted the biggest influence on MA, and when compared to the non-MA group, the MA group's self-efficacy was shown to be higher (P=0.000).Fifth, when MA and INR were examined for connections, in atrial fibrillation patients, MA did not affect INR, and in case of valve surgery patients, MA affected INR in the group that had a higher INR than the treatment range (P=0.037).This paper aimed to analyze factors that affect MA in patients who take warfarin in terms of general characteristics, factors pertaining to disease and medication, knowledge of medication, and self-efficacy. The results show that knowledge of medication and self-efficacy exert significant influence in the MA group. Based on its research, this paper purposes the development of a program for raising knowledge of medication and self-efficacy as factors that affect MA to warfarin.