Those studies focused mostly on the impact of CDs on disability, functional decline and mortality or its relationship with nutrition. In addition to the strength of association between CDs at a specific time point, a longitudinal follow-up design is rarely used in the context of multimorbidity and could help understand causality. To the best of our knowledge, no study has used a longitudinal study design to investigate the evolution of multimorbidity. This study aims to characterize evolution of multimorbidity by 1) characterizing the magnitude of the evolution of the prevalence of multimorbidity through time, 2) determining the order in which CDs appear and 3) identifying CDs present at baseline which are associated with an increased risk of developing other CDs. The North West Adelaide Health Longitudinal Study is a representative population sample of people aged 18 years or older living in the north western suburbs of Adelaide, South Australia and covers a broad range of TWS119 socioeconomic areas. The study��s purpose is to investigate the prevalence of chronic conditions and associated health-DAPT related risk factors, and to monitor progression of diseases over time in order to help plan health care provision. The sample is representative of the community profile of Adelaide and has been described previously in detail. Briefly, between 2000 and 2002, 4060 adults completed a telephone interview, self-completed questionnaire and clinic biomedical assessment. This represents 50% of the people invited to take part in the study. Persons aged $18 years from households selected at random from the electronic white pages directory were eligible. Respondents completed a self-report questionnaire related to health status and additional demographic details and underwent clinical assessment, including measurement of blood pressure, height, weight, fasting glucose and lipid levels. Stage 2 and Stage 3 included a Computer Assisted Telephone Interview, a self completed questionnaire and a biomedical examination at a clinic. For Stage 2, 3564 of the participants were interviewed and/or completed a questionnaire and 81.0% of the eligible sample attended a clinic appointment.