Will a new clinical decision rule be widely used? The case of the Canadian C-Spine Rule

Objectives: The reasons why some clinical decision rules (CDRs) become widely used and others do not are not well understood. The authors wanted to know the following: 1) To what extent is widespread use of a new, relatively complex CDR an attainable goal? 2) How do physician perceptions of the new CDR compare with those of a widely used rule? 3) To what extent do physician subgroups differ in likelihood to use a new rule? Methods: A survey of 399 Canadian emergency physicians was conducted using Dillman's Tailored Design Method for postal surveys. The physicians were queried regarding the Canadian Cervical-Spine Rule (C-Spine Rule). Results were analyzed via frequency distributions, tests of association, and logistic regression. Results: Response rate was 69.29% (262/376). Most respondents (83.6%) reported having already seen the Canadian C-Spine Rule, while 63.0% reported already using it. Of those who did not currently use the rule, 74.2% reported that they would consider using it in the future despite the fact that, compared with another widely used rule (the Ottawa Ankle Rules), the C-Spine Rule was rated as less easy to learn (z = 6.68, p < 0.001), remember (z = 7.37, p < 0.001), and use (z = 5.90, p < 0.001). Those who had never seen the rule before were older (chi((2))(2) = 5.10, p = 0.007) and more likely to work part-time (chi((2))(2) = 7.31, p = 0.026). The best predictors of whether the rule would be used was whether it had first been seen during training (odds ratio [OR], 2.62; 95% confidence interval [CI] = 1.14 to 6.04), was perceived as an efficient use of time (OR, 4.44; 95% CI = 1.12 to 16.89), and was too much trouble to apply (OR, 0.25; 95% CI = 0.08 to 0.77). Conclusions: Widespread use of a relatively complex rule is possible. Older and part-time physicians were less likely to have seen the Canadian C-Spine Rule but not less likely to use it once they had seen it. Targeting hard-to-reach subpopulations while stressing the safety and convenience of these rules is most likely to increase use of new CDRs.