Influence of clinician characteristics and operational factors on recruitment of participants with low back pain: An observational study

Objective The purpose of this study was to identify factors that influence recruitment of patients to an observational study of low back pain (LBP). Methods From 1147 primary care (first health contact) clinicians initially contacted, 138 (physiotherapists and chiropractors) agreed to participate in a large observational study of LBP and were the focus of the current study. Data were collected pertaining to clinicians' characteristics, operational factors, and the number of patients recruited. The association of a variety of clinician characteristics and operational factors with recruitment rate was determined using a multivariate negative binomial regression analysis. Results From October 2011 to November 2012, 1585 patients were screened by 138 study clinicians with 951 eligible patients entering the observational study. Clinicians who were members of their professional association had a recruitment rate less than half that of those who were nonmembers (P <.0001). Clinicians who were trained by telephone had a recruitment rate 4.01 times higher than those trained face to face (P <.0001). Similarly, clinicians who referred a larger number of ineligible participants had a slightly higher recruitment rate with an incident rate ratio of 1.04 per ineligible patient (P <.0001). Other clinicians' characteristics and operational factors were not associated with recruitment. Conclusion This study provides evidence that it is feasible to recruit participants from primary care practices to a simple observational study of LBP. Factors identified as influencing recruitment were professional association (negative association), training by telephone, and referring a higher number of ineligible participants.