Nephro-Urol Mon. 2018 September; 10(5):e82235. doi: 10.5812/numonthly.82235. Published online 2018 September 17. Review Article Adequacy of Dialysis in Iranian Patients Undergoing Hemodialysis: A Systematic Review and Meta-Analysis Fazel Dehvan 1, Fateme Monjazebi 2, Masoumeh Erfani Khanghahi 3, Hiwa Mohammadi 4, Reza Ghanei Gheshlagh 1, * and Amanj Kurdi 5 1Department of Nursing, Faculty of Nursing and Midwifery, Kurdistan University of Medical Sciences, Sanandaj, Iran 2Department of Medical-Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3Department of Educational Management, Faculty of Management and Accounting, Yadegar-e-Imam Khomeini (RAH), Shahre Rey Branch, Islamic Azad University, Tehran, Iran 4Department of Nursing, Brojerd School of Nursing, Lorestan University of Medical Sciences, Lorestan, Iran 5Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, UK *Corresponding author: Assistant Professor, Department of Nursing, Faculty of Nursing and Midwifery, Kurdistan University of Medical Sciences, Sanandaj, Iran. Tel: +98-9144050284, Fax: +98-36235450, Email: [email protected] Received 2018 July 16; Revised 2018 July 25; Accepted 2018 September 06. Abstract Context: Preforming an adequate and effective dialysis is essential to improve patients’ quality-of-life and decrease the complica- tions of kidney failure. However, evidence regarding the effectiveness of dialysis among Iranian patients undergoing hemodialysis is inconclusive. The current study aimed at evaluating the effectiveness of dialysis in Iranian patients undergoing hemodialysis using a systematic approach. Evidence Acquisition: In the current meta-analysis, the search was performed using the keywords “Adequacy of Dialysis” and “He- modialysis Adequacy” in SID, MagIran, ISI/Web of Science, PubMed, and Scopus databases from inception to July 2018. According to the heterogeneity of the studies, the data were analyzed using the random effects model with STATA version 14. Results: The mean urea kinetic modeling (Kt/V) and urea reduction ratio (URR) in Iranian patients undergoing hemodialysis were 1.11% (95% confidence interval (CI): 1.03 - 1.81) and 59.94% (95% CI: 58.33 - 61.54), respectively. There was no correlation between indices of dialysis adequacy, sample size, mean age of samples, and year of the paper publication. However, Kt/V and URR in articles with high methodological quality were higher than the ones with moderate methodological quality. Conclusions: The mean adequacy of dialysis indices among Iranian patients was below the standard levels and it is necessary to consider measures to improve dialysis efficacy. Keywords: Adequacy of Dialysis, Hemodialysis, Iran 1. Context sidered in the treatment of such patients (7). Although patients with ESRD have been successfully treated with Chronic renal failure (CRF) is a set of pathologic pro- hemodialysis over the past four decades, the dialysis com- cesses, characterized by loss of renal function including munity is looking for a valid and simple criterion to reduction in glomerular filtration rate (GFR) and the for- evaluate the adequacy and effectiveness of treatment (8). mation of uremic syndrome (1). End stage renal disease Kalender and Tosun believes that the adequacy of dialy- (ESRD) is the final stage of renal failure, with a GFR of < 15 sis can reduce mortality, increase longevity, and improve mL/minute (2). Globally, approximately 600 million peo- the quality-of-life in patients undergoing hemodialysis (9). ple have CRF, with an annual mortality rate of 60,000 peo- On the other hand, poor and inadequate dialysis means ple (3). The development and prevalence of ESRD in Iran higher disability and mortality rate (10, 11). Effectiveness is higher than that of the global rate, with an estimated and adequacy of dialysis depend on many factors includ- prevalence rate of 1,200 to 1,600 per annum (4,5). ing type of filter, dialysis pump rate, dialysis time and Although hemodialysis, as a substitute for the kid- speed, the application of high-flux dialyzer, blood flow ney, increases the survival and life expectancy in patients, rate, patient education, diet, and underlying diseases (4, it causes several problems such as psychological stress 10). and social isolation of the patients (6); therefore, increas- ing the longevity and quality-of-life should always be con- In general, urea reduction ratio (URR) and urea kinetic Copyright © 2018, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited. Dehvan F et al. modeling (Kt/V) are used to evaluate the adequacy of dial- data, methodologically low-quality articles, and the arti- ysis (12). The urea kinetic modeling represents a fractional cles that lacked full-text were excluded. Data extraction volume cleared of urea per dialysis. The urea reduction ra- was performed using a checklist containing author’s first tio measures the difference in urea levels before and after name, language of the article, year of publication, the con- the dialysis (13). Achievement of a URR of about 65% (equiv- text, the methodological quality score, the sample size, alent to a single pool Kt/V of 1.2) indicates an effective dial- the mean age of the sample size, history of dialysis and ysis (14). Data from different studies show that for every mean body mss index (BMI), and Kt/V and URR indices. To 0.1 increase in Kt/V, the mortality rate decreases by about reduce bias, each article was independently reviewed by 7%, and for every 5% increase in URR, the mortality rate de- two researchers and in case of controversies, they were re- creases by 11% (3). However, evidence from Iranian studies viewed again by a third researcher. The methodological reported wide variation ranging from Kt/V index values of quality of the articles was evaluated based on the strength- 0.58 to 1.6 (15, 16) and URR index values of 47.84% to 69.83% ening the reporting of observational studies in epidemiol- (17, 18). ogy (STROBE) checklist used in various studies to evaluate Due to the importance of adequacy of dialysis in pa- the methodological quality of observational studies (19). tients undergoing hemodialysis, evaluating the effective- ness and adequacy of dialysis in the current study would 3.3. Statistical Analysis help policymakers and healthcare professionals to review Considering the fact that the quality-of-life score had a and revise, if necessary, their current practice toward more normal distribution, the variance of each study was calcu- effective dialysis. Various studies were conducted in differ- lated by the variance of normal distribution: ent regions of Iran to evaluate the adequacy of dialysis in patients undergoing hemodialysis, but there is still no gen- − σ2 var X = eral estimate of the adequacy of dialysis in such patients in n Iran. Moreover, the overall adequacy of dialysis in Iran is not clear in recent years. The weight assigned to each study was proportional to the inverse variance. The mean score of dialysis adequacy indices was estimated and presented with 95% confidence 2. Objectives interval (CI). I2 index and Cochran Q test were used to ana- lyze the heterogeneity of the data. If the I2 index was higher The current study aimed at evaluating the adequacy than 50%, or the probability distribution of the Cochran of dialysis in patients undergoing hemodialysis in Iran Q test was lower than 0.05 (P < 0.05), the random effects through a systematic review and meta-analysis. model was used and otherwise, the fixed effects model was used to estimate the adequacy of dialysis scores. Sensitiv- ity analysis was performed to ensure the stability of the re- 3. Evidence Acquisition sults. Meta-regression model was used to assess the rela- tionship between the adequacy of dialysis and mean age, 3.1. Data Resources and Search Strategy year of publication, methodological quality, and sample The current systematic review and meta-analysis in- size of studies. The probability of publication bias in the cluded observational studies that were published in do- results was investigated by Begg funnel plot. Data analysis mestic and international journals which reported the was performed with STATA version 14, considering the sig- mean and standard deviation (SD) of dialysis adequacy in- nificance level of 0.05. dices (Kt/V and URR) based on the PRISMA (preferred re- porting items for systematic reviews and meta-analyses) guidelines. Two researchers independently searched sev- 4. Results eral domestic and international databases, including Ma- Overall, 117 articles were identified in the initial search, gIran, ISI/Web of Science, PubMed, and Scopus, using the 78 of which were excluded based on our exclusion and in- keywords “Adequacy of Dialysis” and “Hemodialysis Ade- clusion criteria. Finally, 39 articles in Persian and English quacy”. In addition, references of the selected articles were languages met the includion criteria and were selected for also reviewed to gain access to other articles. the study. The oldest and newest studies were conducted in 2001 and 2017, respectively (Figure 1), of which 37 were 3.2. Quality Assessment, Study Selection, and Data Extraction considered eligible to evaluate Kt/V index and 22 eligible to First, all observational