Comparison of estimates and calculations of risk of coronary heart disease by doctors and nurses using different calculation tools in general practice: cross sectional study.
OBJECTIVE
To assess the effect of using different risk calculation tools on how general practitioners and practice nurses evaluate the risk of coronary heart disease with clinical data routinely available in patients' records.


METHODS
Subjective estimates of the risk of coronary heart disease and results of four different methods of calculation of risk were compared with each other and a reference standard that had been calculated with the Framingham equation; calculations were based on a sample of patients' records, randomly selected from groups at risk of coronary heart disease.


METHODS
General practices in central England.


METHODS
18 general practitioners and 18 practice nurses.


METHODS
Agreement of results of risk estimation and risk calculation with reference calculation; agreement of general practitioners with practice nurses; sensitivity and specificity of the different methods of risk calculation to detect patients at high or low risk of coronary heart disease.


RESULTS
Only a minority of patients' records contained all of the risk factors required for the formal calculation of the risk of coronary heart disease (concentrations of high density lipoprotein (HDL) cholesterol were present in only 21%). Agreement of risk calculations with the reference standard was moderate (kappa=0.33-0.65 for practice nurses and 0.33 to 0.65 for general practitioners, depending on calculation tool), showing a trend for underestimation of risk. Moderate agreement was seen between the risks calculated by general practitioners and practice nurses for the same patients (kappa=0.47 to 0.58). The British charts gave the most sensitive results for risk of coronary heart disease (practice nurses 79%, general practitioners 80%), and it also gave the most specific results for practice nurses (100%), whereas the Sheffield table was the most specific method for general practitioners (89%).


CONCLUSIONS
Routine calculation of the risk of coronary heart disease in primary care is hampered by poor availability of data on risk factors. General practitioners and practice nurses are able to evaluate the risk of coronary heart disease with only moderate accuracy. Data about risk factors need to be collected systematically, to allow the use of the most appropriate calculation tools.
McManus
R J
RJ
Department of Primary Care and General Practice, University of Birmingham, Birmingham B15 2TT.
Mant
J
J
Meulendijks
C F M
CF
Salter
R A
RA
Pattison
H M
HM
Roalfe
A K
AK
Hobbs
F D R
FD
D003152:Community Health Nursing / Q000379:methods; D003327:Coronary Disease / Q000209:etiology*; D003430:Cross-Sectional Studies; D004739:England; D005194:Family Practice / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008499:Medical Records; D009720:Nurse Clinicians; D010821:Physicians, Family; D011320:Primary Health Care / Q000379:methods*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity