Exploring the outcomes in studies of primary frozen shoulder: is there a need for a core outcome set?

Purpose In our study we explored the need to define a core outcome set for primary frozen shoulder. Methods We investigated the outcomes used by studies included in a systematic review of the management of primary frozen shoulder; surveyed which primary outcome measures health care professionals considered important; and re-examined papers previously obtained for a systematic review of patients’ views of interventions for frozen shoulder to investigate their views on outcomes. Results Thirty-one studies investigated the outcomes range of movement (28 studies), pain (22), function and disability (22), adverse events (13), quality of life (7) and other outcomes (5). Many different types of pain and ranges of movement were measured. Function and disability was measured using fifteen instruments, the content of which varied considerably. Function and disability, pain and range of movement (132, 108 and 104 respondents, respectively) were most often cited by health care professionals as the primary outcome measure that should be used. Searches identified one paper that included patients’ views. Outcomes of importance to patients were pain at night, general pain, reduced mobility (resulting in modification of activities) and the emotional impact of frozen shoulder. Conclusions We identified a diverse range of outcomes that have been used or are considered to be important. The development of a core outcome set would improve the design and reporting of studies and availability of data for evidence synthesis. Methods used to develop a core outcome set should be robust, transparent and reflect the views of all stakeholders.