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

Kondo et al. BMC Health Services Research 2014, 14:615 http://www.biomedcentral.com/1472-6963/14/615 RESEARCH ARTICLE Open Access Awareness and current implementation of drug dosage adjustment by pharmacists in patients with chronic kidney disease in Japan: a web-based survey Yuki Kondo1,2*, Yoichi Ishitsuka1, Eri Shigemori2, Mitsuru Irikura3, Daisuke Kadowaki4,5, Sumio Hirata4,5, Takeshi Maemura2 and Tetsumi Irie1,5 Abstract 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. Keywords: Adjustment of drug dosage, Community pharmacists, Chronic kidney disease, Web-based questionnaire, pharmacy prescriptions * Correspondence: 1 Department of Clinical Chemistry and Informatics, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto 862-0973, Japan 2 Minaminihon Pharmaceutical Center, 5-15-1 Taniyama-chuo, Kagoshima 891-0141, Japan Full list of author information is available at the end of the article © 2014 Kondo et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Kondo et al. BMC Health Services Research 2014, 14:615 http://www.biomedcentral.com/1472-6963/14/615 Background Chronic kidney disease (CKD) is, an important and common health problem. Its incidence and prevalence are increasing worldwide. The estimated overall prevalence of CKD (glomerular filtration rate <60 mL/min/1.73 m2) 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 Page 2 of 8 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 association’s 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 respondin (...truncated)