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Waiting, quality and outcome

Study
Results
Comment

Waiting times for surgical procedures is not just a British preoccupation. While there are places in the world where operations deemed necessary can seemingly be performed immediately, in many other places patients have to wait for their operation. One such is Canada, where a study demonstrated worse outcomes for patients who have to wait for coronary artery bypass grafts [1].

Study


The study looked at all patients in three Montreal hospitals newly diagnosed as needing CABG over one year ending in December 1994. After some obvious exclusions (like patients needing immediate urgent surgery), there were 266 such patients.

They were interviewed at the time of their enrolment on the waiting list, immediately before surgery, and six weeks and six months after surgery. As well as demographic information and information about their disease severity, symptoms and other medical conditions, the SF-36 was used for quality of life. In additions, major medical events occurring before and after surgery (like myocardial infarction, stroke, death) were recorded from chart review.

Analysis was according to whether patients had their operation before or after the median number of days on the waiting list. Those with a short waiting time waited less than 97 days, the median waiting time. Those with a long waiting time waited more than 97 days.

Results


The average age was 62 years, and 80% were men. The two groups were virtually identical demographically and in disease severity. About 40% had had a prior myocardial infarction.

There were no differences in SF-36 results at baseline. Patients with longer waits had significantly worse scores for several of the eight domains of SF-36 immediately before and six months after the operation, including physical functioning , vitality and general health at both times. Six months after operation physical role and mental health were also significantly worse in patients who had waited more than 97 days than in those who had waited less. Improvements in these domains that occurred after operation in patients with shorter waiting times just did not happen in those who waited longer.

There was no difference between the groups in the occurrence of major medical events before surgery. After surgery, patients with the longer wait had significantly more major medical events (24%) than those with a shorter wait (11%) (Table 1). For every seven patients who waited longer than 97 days, one more had a major medical event postoperatively than if they had a wait of less than 97 days.

Table 1: Major adverse events after CABG according to length of preoperative wait

Percent
Major postoperative event Fewer than 97 days More than 97 days Relative risk
(95% CI)
NNH
(95% CI)
Stroke 5 11 2.4 (0.9 to 5.9)  
Myocardial infarct 2 5 3.5 (0.8 to 17)  
All bad events 11 24 2.3 (1.3 to 4.1) 7.3 (4.4 to 21)

By six months after surgery where the waiting time was less than 97 days, 17 of 20 employed patients (85%) remained employed. Where the waiting time was more than 97 days, 10 of 19 employed patients (53%) remained employed.

Comment


Studies on the effect of waiting time for surgery appear to be rare. It's hardly something that an ethics committee would approve for a randomised trial, so observational studies will be the only form of evidence we get. The strengths of this one were that it was comprehensive (all patients in Montreal for one year), thorough, and by chance the two groups were homogeneous at baseline. What was odd was that it took six years to get to print.

The results will surprise no-one, but rather confirm our observations that ill people go downhill if effective treatment is not forthcoming. It perhaps serves to concentrate the mind on waiting time (all of it, including waiting for a consultant appointment), and remind us that effective management is as important as effective interventions.

References:

  1. J Sampalis et al. Impact of waiting time on the quality of life of patients awaiting coronary artery bypass grafting. Canadian Medical Association Journal 2001 165: 429-433.
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