[Answered]: Smith et al (2003) conducted a study to examine…

Smith et al (2003) conducted a study to examine whether spontaneous losses of early pregnancy are associated with maternal risk of ischaemic heart disease (IHD) in later life. The researchers used routine national maternity data (SMR2) to identify all 129,290 eligible women who delivered their first liveborn infant in Scotland during 1981-5. The Scottish Morbidity Record (SMR) system collects routine discharge data on all patients admitted to the Scottish National Health Service acute (SMR1) and maternity (SMR2) hospitals. The information and statistics Division of the Common Service Agency links all the SMR records for an individual patient to each other and to the General Registrar’s Office death database. The SMR2 system collects information on clinical and demographic characteristics and outcomes. The SMR2 database was used to identify all singleton first births of live baby between 1981 and 1985, inclusive. Stillbirths were excluded because maceration, if present, complicates analysis of birthweight. Infants born alive before 24 weeks of gestation and those with a birth weight of less than 500 g were also excluded. Women who had had previous pregnancies other than induced abortion or miscarriage were not included. Linkage to the SMR1 and General Registrar’s Office databases provided follow-up information on admission to hospital and death (both in hospital and elsewhere) between 1981 and 1999, inclusive, thereby providing between 15 and 19 years of follow-up for all births. Three endpoints were examined: death from any cause, death due to IHD, and any IHD event, whether admission or death. IHD was defined by the international Classification of Diseases (ICD) code of 410-414 (ninth revision) or 120-125 (tenth revision) in the principal position. Hernia repair (both inguinal and femoral) was used as a control hospital-based outcome to assess whether selective migration might explain association with adverse obstetric outcomes. a. What type of the study design is described? Explain b. What are the strengths of this study? c. Why were women who had “infants born alive before 24 weeks of gestation and those with a birthweight of less than