Background: We reviewed studies of in-service interventions for caregivers of persons with dementia in nursing homes published between 1990 and 2004. The aim was to obtain an overview of the evaluated interventions and to characterize their methodological quality.

Methods: A thorough literature search was conducted, including searching electronic databases for selected intervention studies and previous reviews. Selected studies were summarized and compared along certain categories, and methodological quality was assessed.

Results: A total of 21 studies were identified, mostly published in the United States. Most were of poor methodological quality. Although nearly all reported positive effects, their results must be interpreted cautiously due to methodological weaknesses. Extensive interventions with ongoing support successfully demonstrated sustained implementation of new knowledge. Owing to methodological weaknesses and a lack of follow-up evaluations, little or no evidence existed for the efficacy or, particularly, the transfer of knowledge in simpler interventions when reinforcing and enabling factors were not present.

Conclusion: On an international and, particularly, on a national level a lack of evaluated in-service training programs for caregivers in homes for people with dementia is apparent. Methodological weakness is common. This study highlights the need for well-defined methodologically improved studies, providing conclusive evidence of the effects of intervention types to help improve the quality of dementia care.