Cerebrovascular disease as a general medicine discharge diagnosis: assessment of diagnostic agreement on case note review.
BACKGROUND
Accurate clerical coding of discharge diagnoses is important partly because results may be used to derive a recommended costing for hospital length of stays (LOS). Some authors think that discharge coding undertaken by clinicians will result in less diagnostic misclassification than clerical coding. This presupposes a high degree of between-observer diagnostic agreement between clinicians.


OBJECTIVE
To compare discharge coding undertaken by two general physicians, for patients receiving a clerical discharge code of cerebrovascular disease. The recommended LOS was then calculated from each observer's discharge codes using the Physicians Diagnosis Related Group Working Guidebook.


RESULTS
Eighty-two cases were coded as stroke by the clerical coder. Both medical coders agreed with this diagnosis in 68 (83%) of these cases. The corresponding figure for cases coded by the clerical coder as transient cerebral ischaemia was 47% (32/68) agreement between all three observers. Correcting for chance agreement between medical observers using the kappa statistic, a value of 0.64 was obtained for the combined stroke and transient cerebral ischaemia discharges, suggesting moderate diagnostic agreement. Using the clerical coder's results, the mean recommended LOS for all cases of cerebrovascular disease over the study period was calculated at 6.68 days. The corresponding values for the two medical coders were 6.68 days and 6.75 days.


CONCLUSIONS
Diagnostic agreement between clinicians was moderate. Consideration of alternative diagnostic possibilities and the difficulty in determining the duration of neurological deficit were the main reasons for diagnostic disagreement. The mean recommended LOS was similar, however, when comparing results from all three observers.
Lunt
H
H
Christchurch Hospital, New Zealand.
Beard
M E
ME
Wilson
M A
MA
Kendall
D
D
Frampton
C M
CM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003953:Diagnosis-Related Groups; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D015588:Observer Variation; D010351:Patient Discharge; D020521:Stroke