An Overview of Factors Relevant to Undertaking Research and Reviews on the Effectiveness of Treatment for Frozen Shoulder

Abstract

This review summarizes recent research relevant to assessing the effectiveness of treatment for frozen shoulder, including the natural history, the prevalence of frozen shoulder, and other conditions sometimes associated with it. We searched Medline, the Cochrane Database of Systematic Reviews and Embase databases for systematic reviews and randomized controlled trials published in English from 1999 to 2009. Frozen shoulder is of unknown aetiology and has three distinct phases: (1) the painful phase; (2) the stiff (‘frozen’) phase; and (3) recovery (‘thawing’). Frozen shoulder is more common in women and within the age-range 40 years to 60 years. The prevalence of frozen shoulder is between 2% and 5%, but between 10% and 31% in people with diabetes. Diagnosis can prove difficult, particularly within primary care. The many treatment options involve little consensus on usage and in relation to different phases of frozen shoulder. There is limited evidence of the effectiveness of different forms of treatment used for frozen shoulder. Many studies evaluating treatment effects carry a moderate to high risk of bias and omit details of the duration of symptoms or the phase of the condition. The outcome measures used may all lack sufficient specificity. Data on economic outcomes concerning patterns of care, treatment and treatment effects for frozen shoulder are limited.