Intra- and inter-rater reliability of anterior and posterior drawer tests for the assessment of people with shoulder instability

BackgroundThe well-known drawer tests to assess glenohumeral laxity and instability have shown appropriate reliability, although analysed mainly in healthy subjects.ObjectiveTo evaluate the intra- and inter-rater reliability of anterior and posterior drawer tests in subjects with symptoms of shoulder instability.DesignClinometric study of intra- and inter-rater reliability of drawer tests was carried out following COSMIN recommendations and GRRAS checklist.SettingCentres with equipped facilities for assessments.ParticipantsThere were 105 participants (69 male/36 female) aged 18 to 60 years with instability symptoms in at least one shoulder. Each participant underwent bilateral assessments. The sample consists of 210 shoulders, unstable and healthy.InterventionAnterior and posterior drawer tests.Main measuresHumeral translations were assessed using drawer tests and graded with Hawkins scale, modified Hawkins and dichotomising (positive/negative). Two sessions were performed (seven to fourteen-day washout period): Each patient was evaluated by two examiners in the first session and by one of them in the second. Weighted Kappa analysed the reliability.ResultsThe intra-rater reliability of the anterior and posterior drawer tests was <i>excellent (weighted Kappa</i> = 1) with the Hawkins scale. Inter-rater reliability was <i>good</i> for the anterior drawer: <i>weighted Kappa</i> = 0.76 (95%confidence interval: 0.67-0.85) with the Hawkins scale, <i>weighted Kappa</i> = 0.78 (95%confidence interval: 0.69-0.87) with modified Hawkins, and <i>weighted Kappa</i> = 0.80 (95%confidence interval: 0.71-0.89) dichotomising; and for the posterior drawer: <i>weighted Kappa</i> = 0.62 (95%confidence interval: 0.52-0.72), <i>weighted Kappa</i> = 0.67 (95%confidence interval: 0.57-0.78), and <i>weighted Kappa</i> = 0.70 (95%confidence interval: 0.59-0.80), respectively.ConclusionDrawer tests demonstrated <i>excellent</i> intra-rater and <i>good</i> inter-rater reliability in subjects with symptoms of shoulder instability.