the first historical study of quality assessment in the medical field was reported by ernest amory codman , md , of massachusetts general hospital in 1920 . to support his  end results theory, he made public the results of the review of his own hospital in a privately published book ,  a study in hospital efficiency ,  in which he emphasized the importance of patient follow - up and quality assessment . he helped to found the hospital standardization program , which eventually became the joint commission on accreditation of healthcare organizations in 1987 , and the joint commission in 2007 , with the motto  helping health care organizations help patients. from the 1970s through the 1980s , the rapid increase in medical lawsuits and the medical malpractice insurance crisis promoted risk management of medical practices in the united states . in 1989 , the society for thoracic surgeons ( sts ) started to establish national databases   as an initiative to improve quality and patient safety among cardiothoracic surgeons and to respond to strong public opinion about the importance of accountability . in 1997 , an initiative was begun to improve data quality and auditing , and staff were hired to support these efforts . in the sts congenital heart surgery database data specification , ( http://www.sts.org/sites/default/files/documents/congenitaldataspecsv3_22.pdf ) , the patient national identification ( social security number ) is listed , but this field should be collected in compliance with state / local privacy laws . the sts national database complies with the health insurance portability and accountability act , and the federal government protects the sts national database . in 1998 , the sts contracted with the duke clinical research institute ( dcri ) for data warehousing and data analysis . in 1999 , the institute of medicine published a report titled  to err is human : building a safe health system ,  which stated that 44,000 to 98,000 persons die in hospitals as a result of medical errors that could have been prevented . today , the management of the national database is one of the most important tasks of the sts . the database contains three components : adult cardiac surgery , general thoracic surgery and congenital heart surgery ( fig . the sts was the first professional organization to seek approval for its measures from the national quality forum ( nqf ) , a multi - stakeholder health policy organization head - quartered in washington , dc . in this manner , the sts has gained a positive reputation with the government and with health policy organizations . in addition , in 2010 , the sts started to publicly report isolated coronary artery bypass grafting ( cabg ) composite star ratings not only on its own website but also on a consumer report website ( www.consumerreportshealth.org ) . later , public reporting of aortic valve surgery ( avr ) and cabg+avr began , and this year , will be extended to congenital heart surgery . the nqf has been releasing quality indicators in medical fields under the rubric of  nqf - endorsed standards ( http://www.quality-forum.org/home.aspx ) . participation in the sts national database,  operative mortality stratified by the five sts - eacts ( european association for cardiothoracic surgery ) mortality categories, and  risk adjustment in congenital heart surgery ( rachs-1 ) pediatric heart surgery mortality . the sts states on its website that  sts believes the public has a right to know the quality of the surgical outcomes , and considers public reporting an ethical responsibility of the specialty . in turn , in 1998 , at the 7th annual meeting of the asian society for cardiovascular and thoracic surgery in singapore , the need for an asian cardiovascular surgery database was discussed . first , a database ad hoc committee was formed by the japanese society for cardiovascular surgery ( jscvs ) and the japanese association for thoracic surgery ( jats ) ( table 1 ) . moreover , quality improvement of cardiovascular surgery has been discussed by the members of the board of jscvs and jats since early 2000 . in pursuit of this goal , three committees were organized by the jscvs and jats among its academic groups : 1 ) a board certification committee , 2 ) a center aggregation committee , and 3 ) a nurse practitioner and physician assistant committee . in 2000 , before this movement , the japan cardiovascular surgery database ( jcvsd ) was established with close ties to the jscvs and jats . the jcvsd and jscvs invited the founder of the sts national database to discuss starting the construction of the database . the jcvsd established input items comparable to those of the sts national database . in the congenital heart surgery database , the common terminologies and the definitions of congenital heart diseases published in the  annals of thoracic surgery  were adopted , and 193 input items were established in the japan congenital cardiovascular surgery database ( jccvsd ) . thus , the congenital heart surgery databases in the united states , europe , and japan were integrated by using common language in these databases . as a result , although the results were not reported , for example , the discharge mortality in the jccvsd was 0.2% , 0.7% , 3.6% , 7% , and 17.6% for rachs-1 categories 1 , 2 , 3 , 4 , and 5/6 , respectively , during 2008 to 2010 ( fig . this result is comparable to that reported from the sts congenital heart surgery database . unlike the sts national database , the jcvsd employed web - based data collection . data on adult cardiac surgery ( japan adult cardiovascular surgery database [ jacvsd ] ) were collected beginning in 2001 by five participating units and data on congenital heart surgery ( jccvsd ) were collected beginning in 2008 by seven units . jcvsd required informed consent from each patient according to the  opt - in rule to comply with the private information protection law . for web - data transmission , high level secure socket layer was adopted for coding of the individual patient s information . the jacvsd and jccvsd grew to become national databases by the end of 2013 ( fig . the most recent annual number of submitted procedures are 49,507 in jacvsd and 10,835 in jccvsd . twenty frequently cited papers dealing with topics such as risk models of isolated coronary bypass surgery , thoracic aortic surgery , and valve surgery   have been published in indexed international journals . the performance of the congenital heart surgery risk model as measured by the c - index is over 0.8 . on the basis of these risk models , , adult cardiac surgeons can estimate the 30-day mortality rate , in - hospital mortality rate , and major complication rate after inputting the patient s covariates before the surgical procedure . japanscore contributes to obtaining adequate informed consent from the patients and the families , leading to increased satisfaction . in addition , benchmark reports have been released as support tools for quality improvement of participating institutions . in japan , many adult cardiac surgeons learn about the risks faced by their patients , as well as their own performance as a surgeon , through the risk - adjusted mortality and benchmark report . to ensure fairness and transparency in evidence - based medicine ( ebm ) , the jcvsd organized a data access and usage working group . this working group meets twice a year , and requests 100% of their data during at least for the immediate 2-years . after the working group accepts an application , the department of health quality assessment ( hqa ) of the university of tokyo   analyzes the newly submitted data . the role of the hqa is similar to that of the dcri for the sts national database . the members of the working group include two to three adult cardiac surgeons ; visits to 70 sites have been carried out so far . recently the hqa reported the details and outcomes of the site visits to the jccvsd . in 2011 , the jcvsd started to collect a participation fee of 10,000 yen per year for each section in the jacvsd and the jccvsd . the total number of sections was 658 ( 541 in the jacvsd , 117 in the jccvsd ) by the end of april 2014 . this participation fee is much lower than that required by the sts national database ; however , it is an important financial resource , especially for site visits . in 2011 , the japanese board of cardiovascular surgery ( jbcvs ) decided to adopt the data of the jacvsd and the jccvsd for board certification . in 2013 , there were 162 new applicants and 1,003 renewals . the jbcvs held its first web - based and paperless review in september 2013 . compared with the previously employed review method that relied on the submission of operation records , the web - based and paperless review method had higher quality , lower cost , and required less time in 2010 , the jcvsd served as the basis for the establishment of the national clinical database ( ncd ) in japan , which includes clinician - initiated databases reflecting all surgical fields . data collection with the same security level of jcvsd as mentioned above to protect the individual patient s information . through the central institutional review board in the university of tokyo , an  opt - out rule was adopted , and informed consent became unnecessary . the ncd is governed by a committee whose members are representatives of medical associations related to surgery , such as the japan surgical society ( jss ) , jscvs , jats , the japanese association for chest surgery , the japanese society of gastroenterological surgery , the japanese society of pediatric surgeons , the japanese society of vascular surgery , the japanese society of endocrine surgery , the japanese society for mammary cancer , and the japanese thyroid association . the ncd establishes the surgical board certification system for the jss , which requires 13 input items at the first level in the hierarchy of specialties . six board certification systems , including the jbcvs and the databases of nine academic associations , are set at the second level as subspecialties . the main server was transferred from the hqa to the university hospital medical information network ( umin ) with a mirror - image backup . the hqa focused on data analysis and site visits , whereas the umin is responsible for data warehousing . the ncd uses cutting - edge statistical techniques to detect any trace of data inconsistency . the participating associations have supported the ncd financially and the database has grown rapidly ; the total number of participating hospitals is 4105 , and the number of cumulative procedures was 4,138,000 at the end of april 2014 . the participating associations will release , or have released , their own risk models [ 1618 ] , and papers have been published based on data from the ncd . the administrative database , diagnosis procedure combination ( dpc)/par - diem payment system ( pdps ) was introduced in japan by the japanese ministry of health , labour and welfare ( mhlw , a government agency ) in april 2003 to comprehensively assess fixed daily payments and to control medical expenditure in the acute setting based on the quality assessment . the number of participating hospitals by the end of april 2014 was 1,585 , including all advanced - treatment hospitals , that is , university hospitals . in japan , total health care expenditures have been increasing by 1 trillion yen annually , and health care expenditures make up 9.5% of the gross domestic product , which puts japan in the 16th position of the 34 member countries of the organization for economic cooperation and development . on the other hand , the population aging rate in japan is over 24% , which is the highest rate in the world . changes in population makeup and the growing proportion of elderly persons are the underlying issues relating to rising health care expenditures , and successive cabinet office members and the mhlw have set policy directions to address this national issue . quality improvement , quality assessment , and the pay - for - performance system provide methods to control medical expenditures . the quality and outcomes framework ( qof ) , a system for the performance management and payment of genaral practitioners ( gps ) in the national health service in england , wales , scotland and northern ireland was introduced as part of the new general medical services contract in april 2004 . in contrast , in the united states , the agency of healthcare research and quality ( ahrq ) has defined never events or errors of medical care for which medicare , the government healthcare insurance for aged and disabled persons , does not pay . in the c. walton lillehei lecture of the 49th sts annual meeting , the director of the ahrq emphasized that the federal government will pay for the quality , not for the volume . in japan , the ncd and dpc / pdps could play complementary functions for quality assessment through adequate risk adjustment and the complete enumeration of procedures in various surgical fields . in the future , balancing professional autonomy and administrative leadership might be a recurrent issue for quality assessment and quality improvement in japan . recently , the japanese association of cardiovascular intervention and therapeutics proposed to the ncd a comparative study between percutaneous coronary intervention and cabg that would use well - tested statistical methods such as propensity score matching . thus , the participation of units from nonsurgical fields , such as medical therapy , intervention , radiation therapy , and chemotherapy , will facilitate risk stratification of each treatment modality , and will contribute to the search for the best management of diseases and patients . a longitudinal follow - up database is needed for the design of such studies , and it is under construction . recently , the pharmaceutical and medical device agency ( pmda ) , a consultative organization of the mhlw , suggested to enroll in the jacvsd and perform follow - ups on the use of artificial valves for trans - aortic valve implantation . the pmda recognized the completeness and reliability of the data of the jacvsd , and from a cost - performance point of view , the pmda decided to outsource the post - market surveillance of newly covered medical devices in the cardiovascular surgical field . this demonstrates how the national database could contribute to the post - marketing surveillance of drugs and medical devices , and could help control randomized trials and multicenter studies . the ncd will start to collect fees from participating hospitals according to the total number of enrolled surgical procedures . clerical assistants have been widely employed throughout the country , which has gradually lightened the data input workload of young surgeons . governmental support and some government funds clinicians are responsible for patient safety and quality improvement , and the database will aid in achieving these goals . as reinertsen   stated , to truly improve quality , the system must , 1 ) eliminate unnecessary variation ( standardize processes ) , and 2 ) achieve and document continuous improvement ( in care processes and outcomes ) . in recent years , the importance of  certainty , not excellence of operations , and that of the concept of structure , process and outcome   have been emphasized , and multiple approaches , for instance , postgraduate education systems , reporting systems of malpractice to prevent recurrence , introduction of information technology , introduction of simulators , ebm , and other techniques , have been used for patient safety . since it is methodologically based on the jcvsd , the ncd represents an interface between medical databases and board certification systems , which is its point of difference from the sts national database . in 2014 , a new organization for medical board certification was established in japan that , beginning in 2017 , will certify all medical boards in close collaboration with medical associations . this new organization will adopt the standards of the jcvsd and the ncd for evaluating the clinical practices of applicants . for the assessment of medical outcomes and quality , the jcvsd and the ncd will continue to be the sole reliable data source for surgical fields in japan , where medical system reform will be implemented quickly and based on professional autonomy . the national database is fundamental for quality improvement , patient safety , and the adequate control of medical expenditures in the country .
the jcvsd ( japan cardiovascular surgery database ) was organized in 2000 to improve the quality of cardiovascular surgery in japan . 
 web - based data harvesting on adult cardiac surgery was started ( japan adult cardiovascular surgery database , jacvsd ) in 2001 , and on congenital heart surgery ( japan congenital cardiovascular surgery database , jccvsd ) in 2008 . 
 both databases grew to become national databases by the end of 2013 . 
 this was influenced by the success of the society for thoracic surgeons national database , which contains comparable input items . in 2011 
 , the japanese board of cardiovascular surgery announced that the jacvsd and jccvsd data are to be used for board certification , which improved the quality of the first paperless and web - based board certification review undertaken in 2013 . 
 these changes led to a further step . in 2011 , the national clinical database ( ncd ) was organized to investigate the feasibility of clinical databases in other medical fields , especially surgery . in the ncd , 
 the board certification system of the japan surgical society , the basic association of surgery was set as the first level in the hierarchy of specialties , and nine associations and six board certification systems were set at the second level as subspecialties . 
 the ncd grew rapidly , and now covers 95% of total surgical procedures . 
 the participating associations will release or have released risk models , and studies that use 
 big data from these databases have been published . 
 the national databases have contributed to evidence - based medicine , to the accountability of medical professionals , and to quality assessment and quality improvement of surgery in japan .