Do Biochemical Parameters and Intradialytic Symptoms Affect Post-dialysis Recovery Time?: A Cross-sectional Study
Conditions: Dialysis; Complications, Life Quality
Sponsor: Istanbul Demiroglu Bilim University

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Study Protocol 
Official title of the study: Recovery Time and Affecting Factors 
NCT number: NCT04274556 
Date of document: May 11, 2020 
 
Objective: The aim in this study was to investigate the effects of biochemical parameters and 
intradialytic symptoms on post-dialysis recovery time in patients undergoing chronic 
hemodialysis (HD). 
Design: Descriptive and cross-sectional study  
Methods: The study was conducted in accordance with the Declaration of Helsinki. 
Permission was obtained from the local ethics committee (Meeting Date: 2019/07, Decision 
No: 03) and the relevant institutions in addition to written consent from the subjects.  
This study was conducted in a private dialysis center between June and August 2019. The 
inclusion criteria were being on HD for 4 hours a day on 3 days per week for at least 6 
months, aged 18 years or older with no communication problem and volunteering to 
participate in the study. Patients who did not volunteer to participate were excluded. 
 
 
 
 
 
 
 
 
 

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Statistical Analysis Plan 
Official title of the study: Recovery Time and Affecting Factors 
NCT number: NCT04274556 
Date of document: May 11, 2020 
 
Outcome measures 
Post-dialysis Recovery Time: Before the hemodialysis session, the patients were asked by 
the investigators how long it took them to recover from a dialysis session, taking the last 
treatment month into account. 
Intradialytic Hypotension: It is defined in the European Best Practice Guideline (EBPG) as 
a decrease of 20 mmHg or more in the systolic blood pressure or 10 mmHg or more in the 
mean arterial blood pressure together with symptoms requiring nursing intervention. 
Dialysis Symptom Index: It was identified with Dialysis Symptom Index (DSI). DSI consists 
of 30 items. We queried the subjects regarding symptoms in the last 7 days. The effect was 
evaluated with a Likert type scale from 0 to 4, representing "not at all" to "significantly". The 
total score of the DSI ranges from 0 to 150. A score of zero reflects no symptoms while 
increasing total scores reflect increasing effects of the symptoms. 
 
 
 
 
 
 
 
 

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Statistical analysis 
The Statistical Package for Social Sciences (SPSS Inc., Chicago, IL., USA) 22.0 software 
program was used for the statistical analysis of the data obtained from the study. The Shapiro-
Wilk Test was used to determine data normality. Continuous numeric variables were 
presented as mean±standard deviation (SD), median, and interquartile range (IQR), while 
categorical variables were presented as numbers (n) and percentages (%). Comparisons of the 
data without a normal distribution were made by using the ‘Mann-Whitney U Test’ and ‘Chi-
square Test’ while the comparisons of the data with a normal distribution were made with 
‘Student's t Test’. The ‘One Way ANOVA Test’ was used for three-group analysis in case of 
normally distributed variables. Homogeneity of the variables was analyzed with the Levene 
Test. In case of any difference in the multi-group analysis, a post-hoc intergroup analysis was 
done with the Tukey Test. For three-group analysis, the ‘Kruskal-Wallis Test’ and ‘Chi-
square Test’ were used for abnormally distributed variables. Post-hoc intergroup analysis was 
done with the ‘Bonferroni-Corrected Mann-Whitney U Test’. The independent predictors 
among factors affecting the post-dialysis recovery time were evaluated with logistic 
regression analysis by using the possible factors that had been predefined in the previous 
analysis. A P value <0.05 was accepted as statistically significant. 
 
 
 
 
 
 
 
 

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Results