The PACE trial was the first randomized controlled trial (RCT) investigating the efficacy of paracetamol in acute low back pain. Non-compliance to study medication was considered to be a limitation of this RCT. In contrast to conventional statistical methods, complier average causal effects (CACE) analysis may provide unbiased estimates of the effects for participants compliant to paracetamol. Intention to treat (ITT), as-treated, propensity weighted CACE and joint modeling CACE estimates were calculated for pain intensity, disability, global perceived effect and function at two weeks of follow up with compliance defined as an average of at least four tablets per day during the first two weeks of the trial. For pain intensity, exploratory analyses were conducted using additional time points and definitions of compliance.Introduction
Methods
