Risk factors associated with ACL registry compliance: can we predict who will follow-up?

The purpose of this study was to determine patient factors that influence patient compliance to fill out anterior cruciate ligament reconstruction (ACLR) registry forms.

Patients prospectively enrolled in the ACLR registry at a single institution were retrospectively reviewed. Patients who were followed up for at least 6 months were included. Patients who did not fill out initial registry forms were excluded. Patients were asked to fill out forms preoperatively and at 6, 12 and 24 months postoperatively. The impacts of age, race, employment status, medical insurance, smoking status, driving distance to the hospital and importance to return to the same level of sporting activity were analyzed against patient compliance (yes/no) to complete registry forms at the respective follow-ups. Multivariate analysis was performed to analyze variables at 6 and 12 months postoperatively. The numbers of patients who were followed up for more than 24 months were too low to run a multivariate analysis, so only univariate analysis was performed on this cohort.

A total of 221 patients filled out the initial preoperative forms at least 6 months before data gathering was commenced and were included. At 6 months postoperatively, none of the variables significantly influenced patient compliance. At 12 months, younger age and longer driving distance to the hospital had a significant negative impact on compliance [OR per year: 0.92 (0.85-0.99), p = 0.0237; OR per mile: 1.01 (1, 1.01), p = 0.0297]. Patients who filled out registry forms at 6 months were significantly more compliant at 12 months postoperatively (p < 0.0001). At 24 months, the influence of age remained significant (p = 0.0262) and, additionally, patients who initially noted that it was important for them to return to the same level of sports were significantly less compliant (p = 0.0367).

Younger age and longer driving distance to the hospital were significantly associated with less compliance to fill out ACLR registry forms at 12 months postoperatively. Patient perspectives on the importance to return to the same level of sports were inversely related to compliance at 24 months postoperatively. This information can be utilized to improve compliance in future studies as we have potentially identified patients that can be viewed as "at-risk" for registry noncompliance.