IntroductionIn recent years, the prevalence of medication errors inhospitals has become a worldwide concern. In somecases, medical errors are caused by speciFc workerswho intend to cause harm, and in most cases, theseworkers are caught and punished. However, in mostcases, medical errors are typically organizational errors,i.e. they result from a problem in the entire process ofmedical care and not from a single person.Unsafe acts (errors and procedural violations) com-mitted by workers who are in direct contact withpatients or systems are directly related to the occurrenceof medical errors, but the unsafe acts alone rarely leadto the occurrence of a medical error. In Reason’s (1997,2000) model, latent conditions (i.e. error-provokingconditions within the workplace that can create long-lasting holes or weaknesses in the defence) exist behindthe unsafe acts, and it is these conditions that lead tomedical errors. To prevent medical errors, it isimportant to investigate working conditions to deter-mine if they result in errors or safety violations byhealth care workers. It is also necessary to improve themedical care system and working conditions so thatworkers can safely provide medical services.Working conditions that promote unsafe medicalpractice include time pressures, understafFng, inap-propriate tools and equipment, fatigue and inexperi-ence (Reason 1997, 2000). In addition, inadequaterest because of prolonged surgical times and longworking hours, and disturbances in biological rhythmsbecause of shift-work and night work lead to fatigue,shortage of sleep, lower mood and motivation,reduced morale and decreased ability to perform tasksand pay attention (Krueger 1994, O’Shea 1999).These factors all contribute to the incidence of med-ical errors.The relation between working conditions and theoccurrence of medical errors has been studied at var-ious sites. Studies have reported on the occurrence oferrors in relation to stress (Sextonet al.2000, Grasha& Schell 2001, Reilleyet al.2002), shortage of sleep(Dingeset al.1985, Cooper 1989, Doranet al.2001),workload (Leapeet al.1995, Grasha & Schell 2001,Deanet al.2002, Reilleyet al.2002), night work(Roseman & Booker 1995) and fatigue (Williamsonet al.1993, Ganderet al.2000, Sextonet al.2000).Although all of the above working conditions havebeen reported to induce errors, countermeasures havebeen delayed and situations are deteriorating in Japan.±or instance, the number of health care workers inJapan is comparable with other countries, but thenumber of workers per hospitalized patient is lowerthan in many other places. ±or example, according toOECD Health Data for the year 2000, the averagenumber of nurses per 100 beds is 221.0 in the UnitedStates, 120.0 in the United Kingdom, 99.8 in Ger-many, 69.7 in ±rance and 43.5 in Japan. In addition,the workload of each worker in Japan is large, as thenumber of beds is high. ±urthermore, medical institu-tions have been required to streamline medical carebecause of the recent restrictive health care expendi-ture policies. Thus, the length of stays in the hospitalis shortened and bed turnover rate is increased, but thenumber of health care workers remains the same. Theamount of work performed by an individual worker ina given length of time has increased as well. Under theabove conditions, many health care workers are busy,lack sleep, complain of chronic fatigue and think thattheir working conditions lead to medical errors(Tokyo Medical Worker’s Unions Council 2000).According to a report of medical accidents forapproximately 10 000 nurses in Japan (Japan ±eder-ation of Medical Worker’s Unions 2000), factors thatwere considered to lead to medical accidents includedbusy units (n¼9825, 84.6%), shift work fatigue(n¼4877, 42.0%), lack of knowledge and skill(n¼4404, 37.9%) and staff shortage (n¼3553,30.6%).A variety of error prevention measures have beenproposed in Japan to reduce the number of humanerrors in medical care. However, in many of theseprevention measures, the focus is on the medical tasksperformed by health care workers, such as cross-checks, and working conditions are ignored. Conse-quently, the workload is increased further in order toprevent errors, which in turn, leads to the occurrenceof errors. Therefore, it is necessary to investigatewhether the working conditions are causes of themedical errors in the Japanese medical system.However, in contrast to the large amount of qualit-ative research, quantitative research on the relation-ship between medical errors and working conditionsin Japan is limited (Inoue & Koizumi 2004, Suzukiet al.2004).The studyAimThe aim of this study was to explore quantitativelywhich working conditions in²uence the occurrence ofmedical near-miss errors related to intravenous medi-cation at a hospital in Japan.Effects of working conditions on intravenous medication errorsª2006 Blackwell Publishing Ltd,Journal of Nursing Management,14,128–139129
