Psychometric properties and factor structure of the Fertility Problem Inventory in a sample of infertile women undergoing fertility treatment.

OBJECTIVE

to examine the psychometric properties of the Fertility Problem Inventory (FPI) originally developed by Newton et al. (1999); as there are no data concerning the factorial structure of the FPI, a special focus is placed on construct validity through factor analysis.

SETTING

public hospital in Athens, Greece.

DESIGN

a cross-sectional study.

PARTICIPANTS

108 women undergoing fertility treatment with in-vitro fertilisation.

METHODS

the FPI was 'forward-backward' translated from English to Greek. The translated instrument was then administered to a set of infertile women for pilot testing. Principal axis factoring with promax rotation was used to test the factor structure of the FPI. Measures of anxiety State Trait Anxiety Inventory, depression (Center for Epidemiologic Studies--Depression Scale) and mood states Profile of Mood States were used to assess the convergent validity of the FPI. Cronbach's α was used to measure internal consistency of the FPI scales.

FINDINGS

exploratory factor analysis suggested four factors. The majority of relationship and sexual concern items grouped into one solid factor, named 'spousal concern'. The original scales of social concern, need for parenthood and rejection of childfree lifestyle were reproduced after rearranging nine cross-loading items. Construct validity was confirmed by computing correlations between the derived FPI scales and conceptually similar constructions of anxiety, depression and mood states. Internal consistency reliability was satisfactory.

CONCLUSION

the FPI was found to have a relatively stable factor structure and satisfactory reliability, and convergent and discriminant validity. The FPI may enable researchers and clinicians to apply a reliable measure that focuses on various/many dimensions of infertility-related stress.