Qom University of Medical Sciences Journal

Introduction
At the conceptual level, the concept of rumination is an element of the cognitive theory of perfectionism [1, 2]. This conceptualization was based on the initial theory and research conducted by Flett et al. [3]. They suggested significant individual differences in the experience of perfectionistic spontaneous thoughts. According to Felt et al. [4], mistake rumination is a form of self-recrimination, along with other types of self-recrimination found among vulnerable perfectionists. Mistake rumination probably increases avoidance and procrastination and strengthens short-term memories of the past. People who are dominated by thoughts and images of past mistakes are not able to accept themselves unconditionally and have a lower capacity for self-compassion and self-forgiveness. Mistake rumination can initiate, intensify or prolong distress in different ways [4]. People with this tendency experience current distress while remembering the past periods and pay more attention to their imperfect past, which should be problematic due to the inability of perfectionists to accept the past [5]. In general, a perfectionist considers mistake rumination as another proof of her/his inability to adapt and their failure to grow [6].
It is necessary to have a tool to measure mistake rumination to identify people who think a lot about their mistakes so that measures can be taken to prevent their psychological distress. Although there are other questionnaires for measuring rumination, there is no specific tool for measuring mistake rumination. The mistake rumination scale (RMS) was developed by Felt et al. [4] for this purpose which focuses on the actual mistakes in people’s lives. Considering that there is no Persian version of this scale in Iran, this study aims to investigate the psychometric properties of the Persian MRS for the Iranian population.
Methods
This is a descriptive-correlational study. Participants were 270 people aged 18-60 years in Iran who were selected by a convenience sampling method after sending an online invitation from November to December 2022. The questionnaires were created using Google Forms, and their links were sent to people on WhatsApp, Telegram, and Instagram. Of 300 questionnaires, 270 questionnaires were returned. Therefore, the final sample size was 270. Inclusion criteria were consent to participate in the study and no substance abuse. Exclusion criteria were unwillingness to complete the questionnaires and not answering more than 20 questions. The following tools were used to collect data:
Mistake Rumination Scale (MRS): It was developed by Felt et al. [4] to measure a person’s rumination about important mistakes. It has 7 items rated on a scale from not at all to very much, with higher scores indicating greater frequency of mistake rumination. The validity and reliability of this scale has been confirmed by Felt et al [4].
Multidimensional Perfectionism Cognitions Inventory (MPCI): It was developed by Kobori et al. [7] at the University of Tokyo to measure the frequency of the cognitions related to perfectionism and has 15 items and rated on a four-point Likert from 1 (never) to 4 (always) and three dimensions of personal standards (items 3, 5, 8, 10, 11, 14), pursuit of perfection (items 1, 2, 7, 13) and concern over mistakes (items 4, 6, 9, 12, 15). The validity and reliability of this scale has been confirmed [7].
Difficulties in Emotion Regulation (DERS-16): The tool has 16 items developed by Bjureberg et al [8] based on the 36-item version of DERS [9].
Depression, anxiety and stress scale (DASS): This scale has 21 items developed by Lovibond et al. [10] which measures the symptoms of depression, anxiety and stress based on a four-point Likert scale from 0 to 3. This tool has three subscales of depression, anxiety and stress. The reliability and validity of this tool have been confirmed in numerous studies [10 , 11].
Results
In Table 1, the mean and standard deviation (SD) of the scores of the MRS items are presented. Figure 1 shows the confirmatory factor analysis (CFA) model. The factor load matrix showed that all extracted factors in the Persian MRS had loads greater than 0.3 and the distribution of items in the subscales was consistent with the main version.
Discussion
The purpose of the present study was to investigate the psychometric properties of the Persian MRS. There is no research related to measuring the psychometric properties of the MRS in Iran, and this research is the first research in this direction. The results of CFA showed a single-factor solution and all items had a high factor load. The internal consistency of the Persian MRS scale was confirmed by using Cronbach’s alpha coefficient (0.93). The test-retest reliability at an interval of four weeks was also confirmed (0.89). The findings are in line with the results of Felt et al. [4] for psychometric properties of the main version of MRS .
Conclusion
The Persian MRS with 7 items has acceptable validity and reliability. It can be used for measuring mistake rumination in Iran.

The Persian MRS with 7 items has acceptable validity and reliability. It can be used for measuring mistake rumination in Iran.Ethical ConsiderationsCompliance with ethical guidelinesThis study was approved by the University of Mohaghegh Ardabili (Code: IR.UMA.REC.1401.079).FundingThis study was funded by the University of Mohaghegh Ardabili.Authors contributionsAll authors equally contributed to preparing this article.Conflicts of interestThe authors declared no conflict of interest.