Characteristics of study participants. MinassianCaroline L. ThomasSara WilliamsDavid J. CampbellOona SmeethLiam 2013 <p>Abbreviations: IMD = Index of Multiple Deprivation score based on practice post-code (practice level socioeconomic status) or patient post-code (patient level socioeconomic status). The higher the score the greater the deprivation. UTS = up-to-standard (i.e. data meeting GPRD quality standards). ART = assisted reproductive technology.</p>a<p>matching variable.</p>