Implementation of a new guideline in cardiovascular secondary preventive care: subanalysis of a randomized controlled trial

Background: Cardiovascular secondary preventive recommendations are often not reached. We investigated whether a nurse-led telephone-based follow-up could improve the implementation of a new guideline within a year after its release. Methods: In February 2013, a new secondary preventive guideline for diabetic patients was released in the county of Jamtland, Sweden. It included a changed of the low-density lipoprotein cholesterol (LDL-C) target value from <2.5 mmol/L to <1.8 mmol/L. In the Nurse-Based Age-Independent Intervention to Limit Evolution of Disease (NAILED) trial, patients with an acute coronary syndrome, stroke, or transient ischemic attack were randomized to secondary preventive care with nurse-based telephone follow-up (intervention) or usual care (control). Patient data were obtained from the NAILED trial to study the implementation of the new LDL-C guideline by comparing telephone follow-up with usual care. The Mann-Whitney U-test was used for continuous variables, and Person's chi(2) test was used for categorical variables to assess between-group differences. Results: Out of the 1267 patients that entered the study period, 101 intervention and 100 control patients with diabetes fulfilled the inclusion criteria and completed the study period. Before the guideline change, 96 % of the intervention patients and 70 % of the control patients reached the target LDL-C value (p < 0.001). After the guideline change, the corresponding respective proportions were 65 % and 36 % (p < 0.001). The main reason that intervention patients did not achieve the target LDL-C value was that they received full-dose treatment; for control patients, the main reason was that medication was not adjusted, for an unknown reason. Conclusions: One year after a change in the cardiovascular secondary preventive guideline, nurse-based telephone follow-up performed better than usual care to implement the new recommendation.