The Inverted U-shaped Curvilinear Relationship Between Conscientiousness and the Quality of Life in Patients with Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that greatly affects the quality of life. While prior research suggested a linear connection between conscientiousness and health outcomes like quality of life, recent studies propose a more intricate, curved relationship.

The present study aimed to determine the inverted U-shaped curvilinear relationship between conscientiousness and quality of life in patients with irritable bowel syndrome.

This descriptive-correlational study in Tehran’s private gastroenterology clinic in 2020 included 232 IBS patients. Data collected via the NEO Five-Factor Inventory (NEO-FFI) and Irritable Bowel Syndrome Quality of Life (IBS-QOL) questionnaire were analyzed using SPSS version 26 and Excel 2023 for statistical assessment at a 95% confidence interval.

Scatter plots and regression equations demonstrated a strong curvilinear relationship (R2 = 0.14) between conscientiousness and IBS patients’ quality of life, surpassing the linear relationship (R2 = 0.08). Curvilinear regression analysis revealed significant correlations (95% CI) for both the first-degree coefficient (β1 = 2.304, P < 0.001) and the second-degree coefficient (β2 = -2.043, P < 0.001).

The findings indicate an inverted U-shaped relationship between conscientiousness and quality of life in IBS individuals. This underscores the importance of addressing exceptionally high conscientiousness levels in healthcare.