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Background\ud \ud Although covariate adjustment in the analysis of randomised trials can be beneficial, adjustment for continuous covariates is complicated by the fact that the association between covariate and outcome must be specified. Misspecification of this association can lead to reduced power, and potentially incorrect conclusions regarding treatment efficacy.\ud \ud \ud Methods\ud \ud We compared several methods of adjustment to determine which is best when the association between covariate and outcome is unknown. We assessed (a) dichotomisation or categorisation; (b) assuming a linear association with outcome; (c) using fractional polynomials with one (FP1) or two (FP2) polynomial terms; and (d) using restricted cubic splines with 3 or 5 knots. We evaluated each method using simulation and through a re-analysis of trial datasets.\ud \ud \ud Results\ud \ud Methods which kept covariates as continuous typically had higher power than methods which used categorisation. Dichotomisation, categorisation, and assuming a linear association all led to large reductions in power when the true association was non-linear. FP2 models and restricted cubic splines with 3 or 5 knots performed best overall.\ud \ud \ud Conclusions\ud \ud For the analysis of randomised trials we recommend (1) adjusting for continuous covariates even if their association with outcome is unknown; (2) keeping covariates as continuous; and (3) using fractional polynomials with two polynomial terms or restricted cubic splines with 3 to 5 knots when a linear association is in doubt.

Social media has become part of everyday life. By January 2015, over 3 billion internet users had set up more than 3.7 billion active social media accounts (Kemp, cited in Davis and Voyce, 2015). Social media in a professional context offers occupational therapists a powerful communication tool, one they have embraced enthusiastically. An increasing number use it not only to support their continued professional development but also to promote their research among their peers and across international health care networks. There is enormous potential for enabling contact and interaction with colleagues, policy makers, researchers and professional organisations on an equal footing. Recently, even traditional health care organisations, such as the National Health Service (NHS) in the United Kingdom, have facilitated the use of social media by health care professionals, no doubt assisted by its cost efficiencies with reduced cost for time and travel (Lawson and Cowling, 2014). Academic and research organisations likewise recognise that social and online media enrich academic life, whether through using Google Scholar to build research citations, Slideshare to distribute conference presentations, or online groups to collaborate with colleagues.