Students: Tamlin Clulow (& Brenda Cournane)
Supervisor: Dr Ian Sheerin, Dr Alistair Humphrey, Dr Greg Hamilton
Sponsor: Canterbury Rural Primary Health Organisation
Cardiovascular disease (CVD) is New Zealand's leading cause of mortality, accounting for over 40% of deaths. General Practitioners attempt to identify risk factors in patients that could contribute to a future cardiovascular event. To estimate absolute cardiovascular risk, information on a number of risk factors must be collected, in accordance with the New Zealand Guidelines Group (NZGG) recommendations (2). Because cardiovascular disease can be reduced by lifestyle change and drug therapy, it is important to identify an individual's risk promptly. The goal of the current guidelines is to reduce the 5-year CVD risk to less than 15% overall. Risk assessment is recommended for asymptomatic men from the age of 45 and for asymptomatic women from age 55. The screening and prevention of cardiovascular disease is a high priority for the Canterbury District Health Board. They have proposed a 'screen and treat' pilot programme for general practices, where all patients will be screened for risk factors during a routine visit to their general practitioner and then treated accordingly. The current project attempts to provide data on the prevalence of CVD risk factors at a general practice in Rangiora (Practice B) so that when the 'screen and treat' programme is initiated researchers will be able to see what effect it is having in identifying CVD risk factors. During the audit, information on the way GPs at Practice B record information will also be generated.
This project aims to audit the patient records of all 60-74 year olds and identified diabetics enrolled in Practice B and record all documented CV risk factors, as defined by the NZGG.
The MedCen Programme employed at Practice B was used to create a list of enrolled patients aged 60-74. The search engine on this programme was also used to create a list of patients that had diabetes identified in their records. The paper-based files of these patients were then audited for information related to CVD risk. Where all of the necessary information was available, cardiovascular risk was calculated for each patient. Data was then entered into an Excel spreadsheet and analysed using the SPSS statistical software package.
Practice B had 339 enrolled patients between the ages of 60-74 (66.7% female, 33.3% male). For the patients in the 60-74 year old age group 5-year CVD risk was able to be calculated for 61.8% of patients. There were 60 patients with known cardiovascular disease in this age group (17.4%). There were no Maori included in this group. Prevalence was calculated for CVD risk factors in the population and the sex-specific trends of these risk factors. The prevalence of all types of diabetes, personal history of CVD and smoking is higher in the male patient population than the female. The prevalence of a BMI = 30 and recorded family history of CVD is higher in the female patient population than in the male.
Trends in absolute 5 year cardiovascular risk values for the 60-74 year old age group were calculated. This assessment was made for the 213 patients for who adequate information was available. Overall male patients in this age group had a higher 5-year absolute risk than female patients.
There were 88 diabetics (n= 56 female, = 32 male) over 25 years old enrolled at Practice B. A greater percentage of female diabetics smoke and have a BMI = 30. A greater percentage of all diabetics have a past history of CVD (33.4%).
Investigations recommended by the NZGG to be undertaken by GPs were also recorded It was shown that blood pressure, smoking and family history details are commonly recorded. Laboratory tests such as fasting lipids, blood glucose and serum creatinine values are recorded for more than half of patients. Details least likely to be recorded include waist measurements, BMI, the more specific laboratory blood tests and information on physical activity.
The information collected on the recording procedures at Practice B showed that not all recommended information for the assessment of cardiovascular risk was being collected. The fasting TC:HDL ratio was only available for 65.3% of patients. Because this test result is used to calculate a patient's 5-year absolute cardiovascular risk, this value could only be calculated in 61.8% of patients. The lack of information may limit a GP's ability to promptly assess CVD risk and prescribe appropriate lifestyle changes and medications to reduce this risk.
In order to meet the guidelines set by the NZGG, it is recommended that a more comprehensive collection of CVD risk factors be undertaken in the 60-74 year old age group during routine consultations at Practice B. It is also recommended that this Practice consider recording patient data on computer. This format would allow for easy access to and collation of data. Although the aforementioned difficulties collecting data existed, this Practice was found to have similar levels of risk factor recording to the other two practices in the area