Barrett G. 2002 Developing a measure of unplanned pregnancy.
London School of Hygiene and Tropical Medicine, University of London. PhD Thesis.
The incidence of unplanned pregnancy has long been used as an indicator of sexual and reproductive health. However, because of dramatic social and demographic changes, existing measures have become outdated and no satisfactory contemporary measure of this status exists.
The aim of this study was to develop a measure of unplanned pregnancy which is valid, reliable and appropriate in the context of contemporary demographic trends and social mores, and can be used to establish population estimates of unplanned pregnancy. To achieve this, a two-stage study design was employed: firstly, qualitative (inductive) methods in order to delineate the construct of pregnancy planning/intention, and secondly quantitative/psychometric methods to establish the means of measurement. At the qualitative stage, 67 depth interviews were carried out with pregnant (continuing pregnancy and abortion) and postnatal women. A conceptual model of pregnancy planning/intention was developed from these data and used as the basis for item development in the quantitative stage. Standard psychometric techniques were then employed to construct the measure and test its reliability and validity (the qualitative findings informing judgements about content and construct validity). Over 1000 women participated in the psychometric field testing.
The result of the study is a six-item measure of unplanned pregnancy - the first psychometric measure of this construct. Psychometric testing demonstrated the measure's high reliability (Cronbach's alpha >0.90; test-retest reliability >0.90) and high face, content, and construct validity. Women may occupy a range of positions in relation to pregnancy planning, and these are represented in the measure by the spectrum of scores (zero to 12). These scores provide a more sophisticated level of information about pregnancy planning than was previously available. The measure is suitable for use with any pregnancy regardless of outcome (i.e. birth, abortion, miscarriage) and is highly acceptable to women.