BackgroundA multifaceted implementation (MFI) strategy was used to implement an evidence-based occupational therapy program for people with dementia (COTiD program). This strategy was successful in increasing the number of referrals, but not in improving occupational therapists’ (OTs) adherence. Therefore, a process evaluation was conducted to identify factors that influenced the effectiveness of the MFI strategy.MethodsA mixed-method approach of qualitative and quantitative research was used to evaluate the implementation process. The MFI strategy as planned and as executed were reported and evaluated based on the framework of Hulscher et al. (2003; 2006). Data on OTs attitudes and expected barriers were collected at baseline from 94 OTs using a 19-item questionnaire. Data on the experiences were collected after finishing the implementation using focus groups with OTs and telephone interviews with physicians and managers. For quantitative data, frequencies and correlations were calculated and qualitative data were analyzed using inductive content analysis.ResultsThe implementation strategy as executed had a stronger focus than planned on increasing OTs promotional skills due to an initial lack of referrals. This resulted in less attention for increasing OTs’ skills in using the COTiD program as initially intended. At baseline, OTs had a positive attitude toward the program, however, 75% did not feel experienced enough and only 14.3% felt competent in using the program. Focus groups and interviews revealed various determinants that influenced implementation. Most managers were positive about the program. However, the degree of operational support of managers for OTs regarding the implementation was not always adequate. Managers stated that a well-defined place for occupational therapy within the dementia care network was lacking although this was perceived necessary for successful implementation. Several physicians perceived psychosocial interventions not to be in their area of expertise or not their responsibility. All professionals perceived inter-professional collaboration to be a facilitator for effective implementation, and general practitioners were perceived as key partners in this collaboration. However, collaboration was not always optimal. OTs indicated that increasing the referral rate was most effective when promoting OT via other disciplines within a physician’s network.ConclusionOur data suggests that a first step in successful implementation should be to make sure that individual and organizational barriers are resolved. In addition, implementation should be network-based and encourage inter-professional collaboration. Initial promotion of COTiD should focus on physicians that have a positive attitude toward non-pharmacological interventions.