A randomised feasibility trial of an employer-based intervention for enhancing successful return to work of cancer survivors (MiLES intervention).

Background: Employers express a need for support during sickness absence and return to work (RTW) of cancer survivors. Therefore, a web-based intervention (MiLES) targeted at employers with the objective of enhancing cancer survivors' successful RTW has been developed. This study aimed to assess feasibility of a future definitive randomised controlled trial (RCT) on the effectiveness of the MiLES intervention. Also preliminary results on the effectiveness of the MiLES intervention were obtained.

Methods: A randomised feasibility trial of 6 months was undertaken with cancer survivors aged 18-63 years, diagnosed with cancer < 2 years earlier, currently in paid employment, and sick-listed < 1 year. Participants were randomised to an intervention group, with their employer receiving the MiLES intervention, or to a waiting-list control group (2:1). Feasibility of a future definitive RCT was determined on the basis of predefined criteria related to method and protocol-related uncertainties (e.g. reach, retention, appropriateness). The primary effect measure (i.e. successful RTW) and secondary effect measures (e.g. quality of working life) were assessed at baseline and 3 and 6 months thereafter.

Results: Thirty-five cancer survivors were included via medical specialists (4% of the initially invited group) and open invitations, and thereafter randomised to the intervention (n = 24) or control group (n = 11). Most participants were female (97%) with breast cancer (80%) and a permanent employment contract (94%). All predefined criteria for feasibility of a future definitive RCT were achieved, except that concerning the study's reach (90 participants). After 6 months, 92% of the intervention group and 100% of the control group returned to work (RR: 0.92, 95% CI: 0.81-1.03); no difference were found with regard to secondary effect measures.

Conclusions: With the current design a future definitive RCT on the effectiveness of the MiLES intervention on successful RTW of cancer survivors is not feasible, since recruitment of survivors fell short of the predefined minimum for feasibility. There was selection bias towards survivors at low risk of adverse work outcomes, which reduced generalisability of the outcomes. An alternative study design is needed to study effectiveness of the MiLES intervention.

Trial Registration: The study has been registered in the Dutch Trial Register ( NL6758/NTR7627 ).