Validity and reliability of patient assessment of constipation quality of life scale for turkish society

BackgroundChronic constipation not only ruins the patient?s quality of life significantly but also results in substantial financial and labor loss. There are a few specific evaluation forms in use to evaluate the life quality of patients with chronic constipation. The most sensitive one of these forms is PAC-QOL (Patient Assessment of Constipation ? Quality of Life) survey. Diagnosis, symptom evaluation and quality of life surveys differ between cultures depending on the language and disease?s geographical distribution. There aren?t any life quality surveys on chronic constipation in Turkish language, whose validity and reliability has been proven. This study is a descriptive and methodological research planned to define validity and reliability of the ?Patient Assessment of Constipation Quality of Life Scale? for Turkish society.Material and MethodThe study included the patients suffering from constipation, who applied to Dokuz Eylül University Faculty of Medicine Department of Gastroenterology outpatient clinic between January and June 2012. These patients? complaints were consistent with the chronic functional constipation criteria. Research data were achieved from a sample group of 154 patients who filled in the survey form. With regards to its scoring system and structure, ?Patient Assessment of Constipation Quality of Life Scale? is a simple scale developed to measure the effects of chronic constipation on quality of life and daily life activities. ?Patient Assessment of Constipation Quality of Life Scale? consists of total 28 questions. The factor analysis structure of the scale shows that it is comprised of 4 sub-dimensions including ?Physical discomfort?, ?Psychosocial discomfort?, ?Concerns-remarks? and ?Satisfaction?. In hypothesis verification of the scale, constipation symptom assessment was used for criterion validity and SF 36 surveys were used for overlapping validity. The surveys were carried out face-to-face and ?PAC QOL? was filled out by patients again to test the reliability 2 weeks later.ResultsThe age average of 154 persons in this study is 49.45 ± 17.21 years. 72% of the research group is women and 38,3% has education on elementary level. After obtaining necessary permissions, ?PAC QOL? was translated from English to Turkish by ?translation-retranslation? method. Content validity of ?PAC QOL? was tested by specialist?s comments. Internal consistency Cronbach Alpha coefficient of ?PAC QOL? is on good level as 0.89. The scale?s test-retest reliability was found to be r= 0.659, p<0.001. Time validity of the scale was evaluated by ICC (Intraclass correlation coefficient) method and ICC value of all questions in the second week control was confirmed as 0.89. The validity of the scale in the study group was controlled by factor analysis. Our scale data is KMO: 0.857 and Bartlet test p=0.000 which is significant in advanced level. Questions were categorized under two factors according to the factor analysis and these factors explain 65.1% of total variation. In hypothesis verification of the scale, correlation between PAC QOL and SF-36 showed reverse poor relation (r= -0.381, p<0.001). Correlation coefficient between PAC QOL and PAC-SYM was r=0.494 (p<0.001) while the correlation coefficient between PAC QOL and Constipation Severity Score was r=0.411 (p<0.001). Again, significant and poor-medium level of relation was found between these scales.Discussion and SuggestionsIn conclusion of our study, usability of the ?Patient Assessment of Constipation Quality of Life Scale? was found to be reliable but not valid based on the sample group we used this scale for. It wouldn?t be right to generalize the result of a sample group of 154 patients for the entire Turkish society depending on this result. It will be useful to use this scale on more peculiar patient groups (for instance younger people with higher level of education) by changing the scale a little or making necessary adjustments on the language and understandability. When used together with the severity and symptom scoring of chronic constipation patients, this quality of life scale is a useful scale in clinical use as it brings a holistic approach to patient assessment by using two measurement tools simultaneously one being subjective and one being objective.