The Persian version of the revised dyadic adjustment scale (RDAS): a validation study in infertile patients

Infertility can have a powerful impact on marital quality. The Revised Dyadic Adjustment Scale (RDAS) is a widely used measure of marital quality. This scale has not been validated in infertile patients. Therefore, this study aimed to evaluate the reliability and validity of the RDAS in a sample of infertile patients.

The sample of this methodological study consisted of 254 infertile patients referring to a referral infertility clinic in Tehran, Iran. A battery of questionnaires was administered to the participants, including a demographic/fertility questionnaire, the RDAS, the Relationship Assessment Scale (RAS), the Kansas Marital Satisfaction Scale (KMSS), the Couples Satisfaction Index- 4 Item (CSI-4), the Hospital Anxiety and Depression Scale (HADS), and the Perceived Stress Scale-4 Item (PSS-4). Internal consistency of the scale was assessed with Cronbach's alpha, construct validity was investigated using confirmatory factor analysis (CFA), and convergent validity was examined by correlating the RDAS with RAS, KMSS, CSI-4, HADS, and PSS-4 instruments.

The mean total RDAS score was 49.26 ± 9.34, and 100 patients (39.4%) had marital distress based on the cut-off value of < 48. The second-order three-factor model of the RDAS exhibited an excellent fit to the data, as indicated by χ²/df = 2.26; CFI = 0.96; GFI = 0.91; NFI = 0.93; IFI = 0.96; RMSEA = 0.071 and SRMR = 0.050. The RDAS and its subscales revealed satisfactory internal consistency that ranged from 0.664 to 0.847. Convergent validity was confirmed by strong correlations between RDAS scores and scores on the RAS, KMSS, and CSI-4. These correlations also tended to be larger than correlations with measures of HADS-anxiety, HADS-depression, and PSS-4. Among demographic/fertility variables, only infertility duration was found to be correlated to the RDAS.

The RDAS is a reliable and valid inventory for measuring marital quality in infertile patients. Further validation studies are needed to generalize the underlying structure of the scale in various populations.