Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) Applyng Data Mnng Technology on the Usng of Tradtonal Chnese Medcne n Tawan Y-Horng La Departent of Health Care Adnstraton Orental Insttute of Technology New Tape Cty, Tawan Eal: FL006 [AT] al.ot.edu.tw Abstract Ths research eployed the coplete datasets of Tradtonal Chnese edcne (TCM) outpatent reburseent clas fro 005 to 007 to analyze the usng of TCM, the characterstcs of TCM patents, and the dsease categores that were treated by TCM n Tawan. Wth the result of ths study, feale use TCM ore frequently than ale, s consstent wth prevous reports fro western countres. The reasons for ths feale predonance were not fully elucdated n prevous reports. It was suggested that ndependent feales, or feales of good socal status, had hgher expectatons of or belef n TCM n respect of postpartu condtons, enopause and chronc dseases. The age dstrbuton of TCM users peaked n the 0-9 group, followed by the 10-19 group and 31-39 group. Most TCM vsts were to prvate TCM clncs, followed by the prvate TCM hosptals. Accordng to the results, the ost coon reasons for TCM vsts were Kuru (460), Cough (786.), Allergc rhnts cause unspecfed (477.9), Lubago (74.), Headache (784.0), Myalga and yosts, unspecfed (79.1), Constpaton (564.0), Other sleep dsturbances (780.59), Sleep dsturbances, unspecfed (780.50), and Dyspepsa and other specfed dsorders of functon of stoach (536.8). TCM was popular n the Chnese populaton. More and ore subects used TCM at least once durng the 3-year study perod. TCM, lke western edcne, was coonly used by the Chnese populaton for probles and dseases of aor huan organ systes. Ths study provdes nforaton about the use frequences of TCM and dsease categores treated by TCM, whch should be useful for health polcy akers and for those who consder the ntegraton of Chnese and Western edcne. Keywords- Tradtonal Chnese edcne, data nng, dsease coorbdty network, Classfcaton and Regresson Tree (CART) I. INTRODUCTION Tradtonal Chnese edcne (TCM) was an portant topc of copleentary and alternatve edcne n Western opnon [9]. Current TCM practces can be traced back ore than 000 years. TCM was stll coonly used by the Chnese [3]. In Tawan, not untl the 1980s dd several researchers start to research ssues relevant to TCM, usng saplng surveys or studes wth sall saple szes [4]. There has been no largescale nvestgaton of the use of TCM aong Chnese people worldwde, now. Iportance n copleentary and alternatve edcne had ncreased substantally n western countres durng the past decade [1]. Patents and ther fales see to have sought ther health practtoners' opnons about varous copleentary and alternatve edcne odaltes ore frequently []. Many studes have deonstrated draatc ncreases n the use of, and expendture on, copleentary and alternatve edcne n the Western opnon []. However, ost of the prevalent studes of copleentary and alternatve edcne use were based prarly on questonnare surveys, telephone ntervews or collectng data fro nsurance clas, and the saple szes generally were sall. In Tawan, the Natonal Health Insurance (NHI) was started n 1995 and covers nearly all nhabtants (1,653,555 benefcares at the end of 001) [5]. The use of TCM has been rebursed by the NHI snce 1996. Tawanese were free to choose Western edcne or TCM, and were allowed to vst ether publc or prvate edcal facltes. Because all clas data are avalable to researches n electronc for, t could be conduct a study of TCM use aong the Chnese populaton n Tawan. The a of ths study was to conduct a naton-wde survey n order to nvestgate the usng of TCM, the characterstcs of TCM users, and the edcal condtons for whch Tawanese people ost coonly use TCM, by analyzng the NHI clas data fro 1997 to 010. TCM provded by the NHI ncluded Chnese herbal reedes, acupuncture and trauatology anpulatve therapy II. METHODOLOGY A. Data Sources The NHI progra was ntated n Tawan snce 1995 and covers nearly all nhabtants. In 1999, the Bureau of NHI began to release all clas data n electronc for to the publc under the Natonal Health Insurance Research Database (NHIRD) proect. The structure of the cla fles s descrbed n detal on the NHIRD webste and n other publcatons [4]. It could be obtan the coplete TCM cla datasets fro the NHIRD n Tawan. The datasets contaned only the vst fles, ncludng dates, edcal care facltes and specaltes, www.ct.co 50
Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) patents' genders, dates of brth, and the three aor dagnoses coded n the Internatonal Classfcaton of Dsease, 9th Revson, Clncal Modfcaton (ICD-9-CM) forat [6]. To protect prvacy, the data on patent denttes and nsttutons had been scrabled cryptographcally. These vst fles represented all the TCM outpatent actvtes wthn the NHI fro 005 to 007. Insurance benefts were avalable for TCM that ncluded Chnese herbal reedes, acupuncture and trauatology anpulatve therapy, especally for ont dslocaton. In Tawan, TCM s rebursed by NHI only n abulatory clncs, not for npatent care. In addton, only lcensed TCM physcans qualfy for reburseent fro the NHI. B. Study Desgn Although the concept of dsease enttes n TCM was qute dfferent fro that n Western edcne, TCM physcans are requested to follow the standard dagnoses accordng to the ICD-9-CM codng syste when clang reburseent. Coon dagnostc groups for TCM vsts were categorzed accordng to the reclassfcaton of prary ICD-9-CM codes for use n the Natonal Abulatory Medcal Care Survey and Natonal Hosptal Abulatory Medcal Care Survey data n the Unted States. To calculate patents' ages n relaton to the 3-year use frequency of TCM fro 005 to 007, Deceber 31, 007 was taken as the ndex of subtrahend. The denonator was the nuber of people who were nsured durng ths 3-year perod. In order to copare the average nubers of vsts between TCM and Western (allopathc) edcne, t could be obtaned the total nuber of abulatory vsts to Western edcne fro the webste of Departent of Health, Tawan. In addton, we obtaned the saplng cla datasets for abulatory care vsts at Western edcne clncs n order to copare the top ten dsease categores between TCM and Western edcne vsts. The saplng was rando and vst-based but was separated onthly to elnate possble seasonal varatons. Accordng to the NHIRD, these sapled fles were representatve of all utlzaton wthn the NHI n Tawan. C. Methodology Decson tree learnng was a ethod coonly used n data nng. The goal was to create a odel that predcts the value of a target varable based on several nput varables. Each nteror node corresponds to one of the nput varables; there were edges to chldren for each of the possble values of that nput varable. Each leaf represents a value of the target varable gven the values of the nput varables represented by the path fro the root to the leaf. A decson tree was a sple representaton for classfyng exaples. Decson tree learnng was one of the ost successful technques for supervsed classfcaton learnng. For ths secton, assue that all of the features have fnte dscrete doans, and there was a sngle target feature called the classfcaton. Each eleent of the doan of the classfcaton s called a class. A decson tree or a classfcaton tree was a tree n whch each nternal node was labeled wth an nput feature. The arcs cong fro a node labeled wth a feature are labeled wth each of the possble values of the feature. Each leaf of the tree was labeled wth a class or a probablty dstrbuton over the classes. A tree can be learned by splttng the source set nto subsets based on an attrbute value test. Ths process was repeated on each derved subset n a recursve anner called recursve parttonng. The recurson was copleted when the subset at a node has all the sae value of the target varable, or when splttng no longer adds value to the predctons. In data nng, decson trees could be descrbed also as the cobnaton of atheatcal and coputatonal technques to ad the descrpton, categorzaton and generalzaton of a gven set of data. Data coes n records of the for: (x,y)=(x 1, x, x 3,,x k, Y) The dependent varable, Y, s the target varable that we are tryng to understand, classfy or generalze. The vector x s coposed of the nput varables, x 1, x, x 3 etc., that are used for that task. The ter Classfcaton And Regresson Tree (CART) analyss was an ubrella ter used to refer to both of the above procedures, frst ntroduced by Brean, Fredan, Olshen, Stone, [10] Trees used for regresson and trees used for classfcaton have soe slartes, but also soe dfferences, such as the procedure used to deterne where to splt. Used by the CART algorth, Gn purty s a easure of how often a randoly chosen eleent fro the set would be ncorrectly labeled f t was randoly labeled accordng to the dstrbuton of labels n the subset. Gn purty can be coputed by sung the probablty of each te beng chosen tes the probablty of a stake n categorzng that te. It reaches ts nu (zero) when all cases n the node fall nto a sngle target category. To copute Gn purty for a set of tes, suppose takes on values n {1,,..., }, and let f be the fracton of tes labeled wth value n the set. I G ( f ) = f (1 f ) = ( f f ) = = 1 = 1 = 1 f = 1 f = 1 In CART,[10] varance reducton was often eployed n cases where the target varable was contnuous (regresson tree), eanng that use of any other etrcs would frst requre dscretzaton before beng appled. The varance reducton of a node N was defned as the total reducton of the varance of the target varable x due to the splt at ths node: = 1 1 1 1 1 + 1 Iv( N) ( x x ) ( x x ) ( x x ) S S S S St St S Sf Sf where S, S t, and S f are the set of presplt saple ndces, set of saple ndces for whch the splt test s true, and set of saple ndces for whch the splt test s false, respectvely. = 1 f www.ct.co 51
Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) D. Software for Data Mnng IBM SPSS Modeler 14.1 and PAJEK 4.0.1 were the an software used for data lnkage and processng. Descrptve data, ncludng frequences, percentage and eans, are presented. III. RESULTS Aong the 1089885 vald benefcares of the NHI progra at the end of 007, 16153 had used TCM durng the year, wth a total of 1547708 vsts. The annual nuber and percentage of TCM users steadly ncreased fro 005 to 007 (as Table 1). The age dstrbuton of the TCM users peaked n the 0-9, followed by the 10-19 and 30-39 (as Table ), whle the age dstrbuton for vst counts showed a peak n the 40-49 followed by the 30-39 and 0-9. A. Classfcaton and Regresson Tree (CART) Base on the age group and sex, the result of Cart decson tree was as Fgure 1. Predctor portance of age group was.53 and sex was.47 (as Fgure ). Most of the TCM vsts dentfed n the study were perfored n prvate TCM clncs (11586971), followed by prvate TCM hosptals (1677), publc TCM hosptals (45665) and publc TCM clncs (403). Vsts to prvate TCM hosptals decreased yearly, whle vsts to prvate TCM clncs, publc TCM hosptals and others ncreased (as Table 3). TABLE 1 PATIENT USE AND VISIT COUNTS OF TRADITIONAL CHINESE MEDICINE (TCM) WITHIN NATIONAL HEALTH INSURANCE (NHI) FROM 005 TO 007 IN TAIWAN Year Vald benefcares wthn NHI Total No Subects usng TCM New patent Total vsts Feale Male 005 37011 11383 65860 4797 11383 588079 006 36007 110715 6446 4689 43650 571634 007 357667 11344 66145 47099 3111 599603 Total 1089885 337791 196431 141360 188603 1759316 TABLE AGE-SPECIFIC USAGE FREQUENCY OF TRADITIONAL CHINESE MEDICINE (TCM) DURING THE 3-YEAR PERIOD FROM 005 TO 007 IN TAIWAN Age Nuber of total Nuber of subects Nuber of (%) (years) populaton usng TCM TCM vsts 9 43977 13607 30.94 108557 10 19 54409 6006 47.80 17484 0 9 64656 34869 53.93 58758 30 39 64046 33418 5.18 316 40 49 6566 3775 5.38 354501 50 59 46130 4135 5.3 64651 60 69 63 1871 49.07 144838 70 79 19375 8348 43.09 100455 80 8318 574 30.94 30606 TABLE 3 SERVICE VOLUME OF TRADITIONAL CHINESE MEDICINE (TCM) BY FACILITY TYPE FROM 005 TO 007 IN TAIWAN Year Publc TCM Prvate TCM Publc TCM Prvate TCM hosptal hosptal clncs clncs Total 005 150 4400 145 58730 588079 006 1480 41113 157 51556 571634 007 15661 4116 101 54679 599603 Total 45665 1677 403 1586971 1759316 www.ct.co 5
Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) Fgure 1. The result of CART www.ct.co 53
Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) Fgure. Predctor portance Aong the 1947696 TCM vsts, each of the had one, two, or three clncal dagnoses accordng to the ICD-9-CM codng syste. The top ten dseases for TCM vsts were Kuru (7.64%), Cough (5.04%), Allergc rhnts cause unspecfed (3.50%), Lubago (3.07%), Headache.99%), Myalga and yosts, unspecfed (.5%), Constpaton (.43%), Other sleep dsturbances (.0%), Sleep dsturbances, unspecfed (1.8%), and Dyspepsa and other specfed dsorders of functon of stoach (1.80%) (as Table 4). TABLE 4 THE TOP 10 MAJOR DISEASE CATEGORIES FOR TRADITIONAL CHINESE MEDICINE VISITS FROM 005 TO 007 IN TAIWAN Dsease ICD-9-CM Nuber of code vsts (%) Kuru 460 116757 5.80 Cough 786. 75977 3.78 Lubago 74. 519769.58 Headache 784.0 447936.3 Myalga and yosts, unspecfed 79.1 4333.15 Allergc rhnts cause unspecfed 477.9 39814 1.98 Constpaton 564.0 347317 1.73 Dyspepsa and other specfed dsorders of functon of stoach 536.8 5641 1.7 Flatulence, eructaton, and gas pan 787.3 3715 1.18 Other sleep dsturbances 780.59 087 1.10 Others 1604767 76.0 Total 0115535 100.00 Furtherore, t could be analyzed the percentage dstrbuton of aor dsease categores for TCM vsts by age (as Table 5). The results show that Kuru (460), Allergc rhnts cause unspecfed (477.9), Dyspepsa and other specfed dsorders of functon of stoach (536.8), Myalga and yosts, unspecfed (79.1), and Other sleep dsturbances (780.59) were hgher n the 31-39 groups. The results show that Constpaton (564.0) was hgher n the 1-9 groups. The results show that Lubago (74.), Headache (784), and Flatulence, eructaton, and gas pan (787.3) were hgher n the 41-49 groups. The results show that Cough (786.) was hgher n the 41-49 groups. It could be found no sgnfcant dfferences between ales and feales n the percentage dstrbutons of the coonest dsease categores for TCM vsts (Table 6). However, feale subects vsted TCM for Kuru (460), Dyspepsa and other specfed dsorders of functon of stoach (536.8), Constpaton (564.0), Lubago (74.), Myalga and yosts, unspecfed (79.1), Other sleep dsturbances (780.59), Headache (784), Cough (786.), and Flatulence, eructaton, and gas pan (787.3) ore frequently than ales. It also be copared the percentage dstrbuton of aor dsease categores for TCM vsts aong dfferent locatons and the results revealed that Kuru (460), Cough (786.), Lubago (74.), Headache (784.0), Myalga and yosts, unspecfed (79.1), Allergc rhnts cause unspecfed (477.9), Constpaton (564.0), Dyspepsa and other specfed dsorders of functon of stoach (536.8), Flatulence, eructaton, and gas pan (787.3), and Other sleep dsturbances (780.59) were ore coonly seen n clncs than n hosptals (Table 7). www.ct.co 54
Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) B. Dsease Coorbdty Network In these years, the boedcal nforatcs s the research felds of nforaton engneerng. The applcaton of networks to ntegrate dfferent genetc, proteoc, and etabolc datasets has been proposed as a vable path toward elucdatng the orgns of specfc dseases. Ths study appled the 005-007 edcal records of hosptalzaton of Natonal Health Insurance Research Database to construct Tawanese dsease network. Ths study estated the prevalence of all dseases stratfed and calculated cases and ph-correlaton coeffcent as coorbdty n the usng of Tradtonal Chnese Medcne as equaton (1). The dsease network of the usng of Tradtonal Chnese Medcne was constructed wth nodes representng dseases and lnks representng coorbdty as Fgure 3. n nn φ = (1) n n n n )( n n ) ( TABLE 5 PERCENTAGE DISTRIBUTION OF DISEASES CATEGORIES FOR TRADITIONAL CHINESE MEDICINE VISITS BY DIFFERENT AGE GROUPS,005 007, IN TAIWAN ICD-9 code -9 10-19 1-9 31-39 41-49 51-59 61-69 71-79 81-460 19330 16658 143657 05835 00918 133688 7758 39916 10898 477.9 80908 103387 58983 61171 4659 736 1187 6877 1683 536.8 6740 30649 34037 44368 48451 35054 1938 13451 4163 564.0 174 9343 84159 75965 6011 3659 1890 1957 1000 74. 691 18757 67774 100036 117341 9435 61086 45404 14445 79.1 349 8784 74436 8734 97608 7173 37533 4699 6760 780.59 838 6015 5678 46318 58175 46989 1410 1197 355 784.0 4817 5059 58350 100644 114895 75407 39065 375 644 786. 14765 87669 683 11761 11975 96617 64008 43594 1395 787.3 1591 0444 333 46986 508 3516 1999 11999 360 Total 486383 516689 647638 88677 918158 65649 364676 40984 73645 TABLE 6 NUMBER OF VISITS AND PERCENTAGE DISTRIBUTION OF DISEASES CATEGORIES FOR TRADITIONAL CHINESE MEDICINE VISITS BY GENDER, 005-007, IN TAIWAN ICD-9 code Feale Male Unknown 460 708005 459015 55 477.9 197331 0076 31 536.8 144991 111148 10 564.0 79487 6760 10 74. 768 4519 48 79.1 61110 170754 459 780.59 143968 7689 15 784.0 3777 119795 369 786. 47163 33304 60 787.3 14451 9861 103 Total 910900 1873670 59 TABLE 7 PERCENTAGE DISTRIBUTIONS OF DISEASES CATEGORIES FOR TRADITIONAL CHINESE MEDICINE VISITS BY LOCATION, 005-007, IN TAIWAN ICD-9 code Publc Prvate Publc Prvate TCM hosptal TCM hosptal TCM clncs TCM clncs Others 460 7414 44936 198 111504 0 477.9 656 5469 101 316831 1 536.8 10543 155 154 309 0 564.0 1073 4147 08 310885 4 74. 14104 4446 3 460971 0 79.1 16111 5615 195 35980 0 780.59 911 4155 31 13778 0 784.0 5731 19889 165 4149 786. 11174 31897 347 716309 0 787.3 507 883 56 355 0 Total 111695 304414 1687 436996 7 www.ct.co 55
Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) Fgure 3. The dsease coorbdty network of the usng of tradtonal Chnese edcne (Ph-correlaton>.5) IV. DISCUSSION AND CONCLUSION After all, ths study s the frst extensve survey of TCM use n Chnese socety. Only wth the help of a coputerzed nsurance reburseent database could such a large-scale TCM utlzaton study feasbly be analyzed. Prevous studes fro western countres on the frequency and characterstcs of TCM use have anly conssted of surveys of clnc attendees, telephone ntervews, wrtten surveys, household ntervews, and hosptal and prvate clnc surveys; and the saple szes have been lted. In addton, the use of TCM n western countres s usually not covered by nsurance [7]. Thus, the survey results ght be affected by the soco-econoc status of the subects [8]. Fortunately, TCM s rebursed by NHI n Tawan, so the study would see to be less based. The use of TCM n western countres has ncreased draatcally n recent years [9]. It goes wthout sayng that TCM had been coonly used n Asan countres, especally n the Chnese populaton, for centures [4]. Owng to the dfferent defntons of copleentary and alternatve edcne, the types of copleentary and alternatve edcne surveyed, survey ethodologes and types of copleentary and alternatve edcne rebursed by nsurance, t was dffcult to copare the use frequency of TCM aong countres [11]. Accordng to the results, there was a steady ncrease n the annual nuber of TCM users n Tawan between 1997 and 010; ths does not nclude folk edcne, whch s not rebursable by nsurance. Chnese people beleve that Western edcne ay react faster to the target but also causes ore adverse sde effects, whle TCM reacts slowly but s subtle and safe [8,9,10]. Furtherore, the nsurance coverage for TCM vsts ght also play a sgnfcant role [8]. It was nterestng to know how health care was used when both Western edcne (WM) and TCM were avalable n Tawan. Table 8 copares the use frequences of outpatent vsts between TCM and WM. The results show that people vsted WM clncs ore coonly than TCM clncs for ther llnesses. Notably, the average nuber of outpatent vsts per person per year n both TCM and WM decreased on 006. WM stll decreased on 007, but TCM ncrease on 007. TABLE 8 COMPARISON OF THE AVERAGE NUMBER OF OUTPATIENT VISITS PER PERSON PER YEAR BETWEEN TRADITIONAL CHINESE MEDICINE (TCM) AND WESTERN MEDICINE (WM) FROM 005 TO 007 IN TAIWAN Year Vald benefcares Total TCM vsts change fro prevous year (%) Total WM vsts change fro prevous year (%) 1997 1154103 10445935 - -1078168 1998 1390066 1137075 7.57 115991 6.94 1999 1983433 11786995 4.89 1196438 3.77 000 1876760 1170886 -.67 1168474 -.34 001 1936 1174184 0.9 1190798 1.91 00 1335493 101454.3 1139.56 003 13301940 1196457 -.41 1337368 9.51 004 14805381 13313138 11.7 14943 11.58 www.ct.co 56
Internatonal Journal of Coputer and Inforaton Technology (ISSN: 79 0764) 005 15037163 1357000 1.93 1467161-1.68 006 1475405 1848000-5.3 147405 -.71 007 1434995 189753 -.14 14954 4.75 008 1414089 1666665-1.7 154744 3.49 009 14668653 1308641.86 164001 5.98 010 14598864 13035699.05 1563165-4.69 Wth the result of ths study, feale use TCM ore frequently than ale, s consstent wth prevous reports fro western countres. The reasons for ths feale predonance were not fully elucdated n prevous reports. It was suggested that ndependent feales, or feales of good socal status, had hgher expectatons of or belef n TCM n respect of postpartu condtons, enopause and chronc dseases. The age dstrbuton of TCM users peaked n the 0-9 group, followed by the 10-19 group and 31-39 group. Most TCM vsts were to prvate TCM clncs, followed by the prvate TCM hosptals. Accordng to the results, the ost coon reasons for TCM vsts were Kuru (460), Cough (786.), Allergc rhnts cause unspecfed (477.9), Lubago (74.), Headache (784.0), Myalga and yosts, unspecfed (79.1), Constpaton (564.0), Other sleep dsturbances (780.59), Sleep dsturbances, unspecfed (780.50), and Dyspepsa and other specfed dsorders of functon of stoach (536.8). TCM was popular n the Chnese populaton. More and ore subects used TCM at least once durng the 3-year study perod. TCM, lke western edcne, was coonly used by the Chnese populaton for probles and dseases of aor huan organ systes. Ths study provdes nforaton about the use frequences of TCM and dsease categores treated by TCM, whch should be useful for health polcy akers and for those who consder the ntegraton of Chnese and Western edcne. ACKNOWLEDGMENT Ths study s based n part on data fro the Natonal Health Insurance Research Database provded by the Bureau of Natonal Health Insurance, Departent of Health and anaged by Natonal Health Research Insttutes. The nterpretaton and conclusons contaned heren do not represent those of Bureau of Natonal Health Insurance, Departent of Health or Natonal Health Research Insttutes. REFERENCES [1] Ahad, A.W. Deternants of copleentary alternatve edcne (CAM) use, Copleentary Therapes n Medcne, vol. 1, pp. 99-111, 004. [] Burg, M.A., Hatch, R.L., & Nes, A.H. Lfete use of alternatve therapy: A study of Florda resdents, Southern Medcal Journal, vol. 91, pp. 116-1131, 1998. [3] Chen, F.P., Kung, Y.Y., Chen, T.J., & Hwang, S.J.: Deographcs and patterns of acupuncture use n the Chnese populaton: The Tawan experence, Journal of Alternatve and Copleentary Medcne, vol. 1, pp. 379-387, 006. [4] Lee, C.H., Chou, Y.J., Chen, L.S., & Chang, H.J. Utlzaton of abulatory Chnese edcal servces under the Natonal health Insurance n Tawan, Tawan Journal of Publc Health, vol. 3, pp. 100-107, 004. [5] Cheng, S.H., & Chang, T.L. The effect of unversal health nsurance on health care utlzaton n Tawan: results fro a natural experent, JAMA, vol. 78, pp. 89-93, 1997. [6] Lu, J.Y., Chen, T.J., & Hwang, S.J. Concotant prescrpton of nonsterodal ant-nflaatory drugs and antacds n the outpatent settng of a edcal center n Tawan: A prescrpton database study, European Journal of Clncal Pharacology, vol. 57, pp. 505-508, 001. [7] Cleary-Guda, M.B., Okvat, H.A., Oz, M.C., & Tng, W. A regonal survey of health nsurance coverage for copleentary and alternatve edcne: Current status and future rafcatons, Journal of Alternatve and Copleentary Medcne, vol. 7, pp. 69-73, 001. [8] Wolsko, P.M., Esenberg, D.M., Davs, R.B., Ettner, S.L., & Phlps, R.S. Insurance coverage, edcal condtons, and vsts to alternatve edcne provders- results of a natonal survey, Archves of Internal Medcne, vol. 16, pp. 81-87, 00. [9] Esenberg, D.M., Davs, R.B., Ettner, S.L., Appel, S., Wlkey, S., Van Ropay, M., & Kessler, R.C. Trends n alternatve edcne use n the Unted States, 1990 1997: results of a follow-up natonal survey, JAMA, vol. 80:1569-1575, 1998. [10] Brean, L., Fredan, J. H., Olshen, R. A., & Stone, C. J. lassfcaton and regresson trees. Monterey, CA: Wadsworth & Brooks/Cole Advanced Books & Software. ISBN 978-0-41-04841-8, 1984. [11] Zollan, C., & Vckers, A. ABC of copleentary edcne: Users and practtoners of copleentary edcne, BMJ, vol. 319, pp. 836-838, 1999. www.ct.co 57