Chronic diseases are the epidemic of the 21st century. They are presenting South Australia, and indeed the world, with a staggering economic and quality of life burden, and major prevention and management challenges.
The North West Adelaide Health Study (NWAHS) is a cohort study of chronic disease and health-related risk factors, from both self-reported and biomedically measured information, established to help provide better health for people living in the north-western region of Adelaide. It is one of the first regions in Australia to make a comprehensive health assessment of the community. Cohort studies follow a group of people with a similar characteristic: in this case, people who lived in the study area at the time of recruitment. This study design allows us to examine how peopleís health either improves, stays the same or gets worse over time and the possible causes for this.
Ongoing support from the participants is vital to the success of the study and the study team sincerely appreciate their generosity in the giving of their time, effort and goodwill. By taking part in the study, participants provide valuable information about other people like them in the wider community, who may be in a similar age group or gender and who may have similar health issues. Adults of all ages, occupations, and states of health have been included in this longitudinal study since its inception in 1999. As well as helping to improve their own health through better awareness of their health and wellbeing, those selected to participate in the study also represent other people like them in the population. Their involvement will have an effect on the health of many other people in their neighbourhoods as well as the wider community.
The cohort study comprise a randomly selected sample of approximately 4000 adults who were recruited during Stage 1 of the study, between December 1999 and July 2003. As part of this baseline examination, participants were invited to answer questions about their health, and visit a hospital clinic for a simple health check. This first stage of the study had a focus on measuring some chronic conditions (such as diabetes, asthma, and chronic obstructive pulmonary disease (COPD), which is sometimes known as chronic bronchitis and emphysema) and risk factors (such as smoking, obesity, high blood pressure, and high cholesterol). For a description of what the tests have involved so far, please click here. Everyone who takes part in the clinical examination of the study receives the results of their tests and is encouraged to discuss these with their doctor.
Stage 2 of the study was conducted between May 2004 and February 2006. Just over 90% of participants helped by completing the telephone and postal questionnaire, and approximately 80% of the cohort returned for their second clinic visit. The focus of Stage 2 was expanded to include additional chronic conditions such as arthritis, osteoporosis, and cardiovascular disease. This follow-up allowed changes in the health status of the community over time to be assessed and the differences explored.
The longitudinal nature of the cohort study means that following Stage 2, the study team now have valuable information about the number of people who are developing these conditions over time, and the factors that increase the risk of developing chronic disease. The results show that the concern expressed about chronic disease and the associated risk factors are indeed true and the situation calls for urgent and sustained action. In addition, there are many positive stories in the results, particularly regarding people adopting healthier lifestyles.
Telephone follow-up surveys (held in 2002 and 2007) between major stages provide ongoing contact with participants, as well as allowing the investigation of other related research topics.
Stage 3 of the study was conducted between June 2008 and August 2010. Once again, we sent out letters to participants to let them know they could expect a telephone call within a week or so, inviting them for their next free health assessment. Once a clinic appointment was made, we sent out an information pack with materials about the appointment, including a map of where to find the clinic, as well as two questionnaires to return to the clinic and a urine sample jar.
Once again, we investigated diabetes, asthma, chronic obstructive pulmonary disease, mental health and arthritis, and a number of risk factors that might predict developing disease at a later stage of life. New areas to be investigated include food and nutrition intake, how people understand health information, genetic aspects of disease and how we can link individual health data to other health-related databases. Some groups of participants may be invited to help us in related sub-studies that explore aspects of chronic disease.
From 2008, one child living in each participantís household has also been invited to participate in this important cohort study. This is so study researchers can start to look at links between the health of family members who live in the same household, and has developed as part of the South Australian Population Health Intergenerational Research (SAPHIRe) Project, a collaboration of four existing cohorts including the Australian Longitudinal Study of Ageing (ALSA); the Florey Adelaide Male Ageing Study (FAMAS); the Whyalla Intergenerational Study of Health (WISH) and the NWAHS.
Based on this vital population data, the North West Adelaide Health Study has become an important research activity which is providing much of the evidence for the magnitude of the chronic disease problem and relevant risk factors. It also enables the measurement of the effectiveness of strategies in preventing and managing chronic disease. The results from the study are an important resource available to health planners, service providers, policy makers and community members and should stimulate the whole community to develop sustainable strategies to reduce the chronic disease burden.
The study is an important collaboration between government (SA Health), health services (The Queen Elizabeth Hospital, Lyell McEwin Hospital and the Institute of Medical and Veterinary Science) and academia (The University of Adelaide and University of South Australia). The North West Adelaide Health Study is being conducted by experienced medical and epidemiological researchers. You can read more about them here.
As part of keeping our cohort participants and other interested parties informed, we provide an annual newsletter which contains information about past, present and future developments of the study. Previous editions of the newsletters are below: