Awareness and current implementation of drug dosage adjustment by pharmacists in patients with chronic kidney disease in Japan: a web-based survey

Yuki Kondo 0 1 Yoichi Ishitsuka 1 Eri Shigemori 0 Mitsuru Irikura Daisuke Kadowaki Sumio Hirata Takeshi Maemura 0 Tetsumi Irie 1 0 Minaminihon Pharmaceutical Center , 5-15-1 Taniyama-chuo, Kagoshima 891-0141 , Japan 1 Department of Clinical Chemistry and Informatics, Graduate School of Pharmaceutical Sciences, Kumamoto University , 5-1 Oe-honmachi, Chuo-ku, Kumamoto 862-0973 , Japan Background: The aims of this study were to evaluate the current awareness of and implementation by pharmacists in Japan of adjustment of drug dosage according to renal function (ADDR) in patients with chronic kidney disease (CKD) and to clarify the factors influencing implementation of ADDR by community pharmacists. Methods: We conducted a web-based questionnaire of Japanese community and hospital pharmacists. Responders were compared by characteristics, rate of implementation of ADDR, experience with adverse drug events, pharmacist awareness of implementation of ADDR, and obstacles to ADDR implementation experienced by pharmacists. Additionally, the factors influencing the implementation of ADDR by community pharmacists were investigated by logistic regression analysis. Results: Fewer community pharmacists had implemented ADDR than hospital pharmacists. The community pharmacists had less experience with adverse drug events caused by an inappropriate dosage than the hospital pharmacists, while the hospital pharmacists had encountered more severe adverse drug events than the community pharmacists. The community pharmacists had less awareness of ADDR implementation, and believed that problems in implementing ADDR were caused by a lack of information on the renal function of patients. In the logistic regression analysis, the factors influencing implementation of ADDR were Routinely receiving prescriptions from nephrologists, Experience with adverse drug events caused by inappropriate dosage for CKD patients, and Awareness of the need for pharmacists to check the dosage of renally excreted drugs; they did not include Lack of information on patient renal function. Conclusions: This study indicates that fewer Japanese community pharmacists than hospital pharmacists implement ADDR and that implementation of ADDR by community pharmacists is hindered by their limited awareness of the importance of patient renal function. We advocate that many countermeasures be introduced to prevent CKD patients from experiencing adverse drug events caused by inappropriate dosage. Such countermeasures would include a training program to educate pharmacists about the impact of impaired renal function on dosage of drugs that are excreted by the kidneys. - Background Chronic kidney disease (CKD) is, an important and common health problem. Its incidence and prevalence are increasing worldwide. The estimated overall prevalence 2 of CKD (glomerular filtration rate <60 mL/min/1.73 m ) in adults (aged 18) is increasing exponentially in the older population in Japan [1]. Pharmacokinetics are often altered in CKD patients [2]. In particular, the optimal dosages of renally excreted drugs are strongly affected by renal impairment. Dosages that do not take renal function into account are a major cause of increases in drug blood concentrations that lead to adverse drug events [3,4]. Appropriate dosages of renally excreted drugs can be calculated on the basis of renal function using creatinine clearance. Thus, dosage adjustment based on renal function contributes to a reduction in the incidence of adverse drug events in older patients and others with renal impairment [5-7]. Adjustment of the drug dosage according to renal function (ADDR) by pharmacists, as a result of checking renal function and recommending alterations in their prescriptions, can prevent inappropriate dosages and thus reduce the incidence of the resulting adverse drug events [8,9]. Hassan et al. [6] reported that hospital pharmacists can contribute to a reduction in the incidence of adverse drug events in patients with renal impairment. Conversely, the contribution of community pharmacists to ADDR seems limited in Japan [10] and in other countries [11]. Although hospital pharmacists can easily obtain information on patient renal function from medical records, community pharmacists may find it difficult. We might expect that the limited contribution to the implementation of ADDR by community pharmacists might be because of the unavailability of information on patient renal function in community pharmacies. However, the practical reasons remain unclear. We conducted Table 1 Questionnaire on pharmacotherapy for CKD patients Work experience (years) Medical departments from which prescriptions are routinely received Experience with adverse drug events caused by inappropriate dosage for CKD patients Implementation of ADDR Awareness of pharmacotherapy of CKD patients Four items, using a 5-point Likert-type scale a questionnaire-based survey to evaluate the current awareness of community pharmacists of ADDR for CKD patients in Japan and to compare the responses of community pharmacists with those of hospital pharmacists. Additionally, to clarify why community pharmacists are not implementing ADDR, we explored factors influencing its implementation. Methods Study design A web-based survey was developed to investigate various factors relating to the pharmacotherapy of CKD patients. A web-based questionnaire has advantages that include access to individuals in distant locations, the ability to reach difficult-to-contact participants, and the convenience of having automated data collection, which reduces researcher time and effort [12]. The survey was conducted via the Internet using Google Forms, a questionnairestyle information-collecting system for efficiently administering questionnaires [13]. The items in the survey are listed in Table 1. Pharmacists were invited to participate via the relevant pharmacist associations mailing lists in each geographical area and via pharmacists groups on social networking sites. Because the URL of the survey website consisted of a random character string, general surfers of the Internet could not access the site. The timeframe for responding was 1 month (from May 1st to 31st, 2013). We did not send any reminders. The survey data were compared with Japanese national statistics on pharmacists from the Survey of Physicians, Dentists and Pharmacists 2012 by the Ministry of Health, Labour and Welfare [14]. We had estimated the percentage of pharmacists with <5 years working experience by the age distribution from the national statistics. The Ethics Committee of Kumamoto University approved the study (no. 788). Community pharmacist/Hospital pharmacist <5, 59, 1020, >20 Multiple choice format/17 departments (general internal medicine, respiratory medicine, gastroenterology, nephrology, endocrinology, hematology, psychiatry, pediatrics, orthopedics, dermatology, ophthalmology, urology, surgery, otorhinolaryngology, dentistry, obstetr (...truncated)