Sexual and reproductive behaviour and health in a birth cohort

Abstract

This portfolio comprises original work published from 1993 to the present that I have undertaken in the area of sexual and reproductive behaviour and health in this study. I originally worked with Professor Charlotte Paul at the age 18 assessment in 1990/1. Since then I have been its Principal Investigator in this area of the DMHDS and have secured funding from the Health Research Council of New Zealand at the age 21, 26 and 32 year old assessments, and am currently leading a team continuing this study at age 38. Therefore I have taken a major role in the collection of data, planning of the analyses and publication of the findings over the past two decades.

When the current assessment is complete, comprehensive information on sexual behaviour will have been collected over a 20 year period covering late adolescence and early adulthood, making this study unique internationally. To be able to link this to the wide range of information collected in other aspects of the DMHDS has created many valuable opportunities optimised by the very low loss to follow up of the participants that can be a major problem in such studies.

Within the field of sexual and reproductive behaviour and health, the papers included in this portfolio predominantly examine a range of issues related to the epidemiology of sexual behaviour, sexually transmitted infections, and sexual orientation. Also included is published work on the relationship between health seeking and sexual behaviour, and of reports of the wantedness of pregnancies up to age 26 years. Of the main 22 papers that investigated these areas, I have been the first author on 10, and a major contributor on the remainder. I have also listed 10 publications of work primarily undertaken by other investigators in the DMHDS - generally research psychologists - that included data on sexual behaviour and/or outcomes sucl1 as sexually transmitted infections that I was responsible for collecting in which I had a more minor contribution.

The analyses reported have used the information collected on sexual and reproductive behaviour and health in various ways. Particularly early in the study, the emphasis was on examining the prevalence of certain behaviours such as early sexual intercourse and health issues such as sexually transmitted infections and where possible the circumstances of these. In addition we explored preceding socio-demographic and behavioural factors; much had been collected prospectively from the participants or their families. With time, and the collection of similar information at a number of assessments, a strength of a cohort study is its ability to examine changes and stability in behaviour, and in the incidence of outcomes such as sexually transmitted infections. Once the data from the age 38 assessment became available truly unique opportunities arose to examine behaviours and outcome over various age periods in early adulthood to examine how these might persist or change. Details of the key findings are discussed after the listing of the papers.

Throughout this period data has been shared with other principal investigators in the study, particularly Professors Moffitt and Caspi, research psychologists, who have utilised them as one of a number of outcomes to get a comprehensive picture of the relationship between a range of psychological or related factors and health outcomes.

In the list of publications, and on the coversheet preceding each of these, I have explained my involvement in each, the number of times it has been cited (as obtained using Google Scholar on 23rd December 2011), and the Impact Factor of the journal (accessed in 2010) in which it was published. Many of the important papers related to sexually transmitted infections and behaviour have been published in the journals Sexually Transmitted Diseases and Sexually Transmitted Infections, which are the top rated journals in this specialist area published US and UK respectively.

The submitted work is original. Two of the papers (#8 and 15) are based on work submitted by Dr Sandhya Ramrakha for her PhD, for which I was a supervisor, and two (#3 and 21) have been include in the portfolio submitted by Professor Peter Herbison for a Doctor of Science thesis at the University of Otago. [--from Introduction]