Norwood 1989.

Clinical features and settings	Inclusion criteria Operative repair or reconstruction for a complete rotator cuff tear Exclusion criteria Rotator cuff tear associated with fracture or dislocation Duration of symptoms Most of Group 1 (see Participants, below) had had symptoms for a mean of 30 months before operative treatment. Previous treatments 75% of Group 1 had received previous 'extensive treatment' for chronic symptoms; only 33% of Group 2 had had previous symptoms sufficiently severe for them to seek treatment. Care setting Tertiary care
Participants	USA (1976‐1984) 103 shoulders in 103 patients (75% male); mean age 54.1 years (SD not reported, range 18‐73). These were subgrouped into individuals with single tendon tears (n = 28; Group 1) and those with multiple tendon tears (n = 75; Group 2). There was an additional control group, data for which were not presented in a usable format.
Study design	Retrospective, cross sectional study with consecutive recruitment
Target condition and reference standard(s)	Distinguishing single tendon tears from multiple tendon tears Operation (presumably open surgery) Procedure No details were given. Interpretation Criteria for a positive result were [1] tears restricted to the tendinous insertion above the spine of scapula (defined as single tendon tears) and [2] tears extending posteriorly below this level (involving infraspinatus with or without teres major) or anteriorly (involving subscapularius) (defined as multiple tendon tears). [3] Additionally noted were calcific deposits, ruptures of the LHB, and tears of the glenoid labrum. Interval between index and reference test Not reported Testers No information given Prevalence 73% (multiple tendon tears)
Index and comparator tests	Active abduction Procedure No details were given. Interpretation The criterion for a positive result was inability to abduct to > 90°. This criterion may have been defined retrospectively.
Follow‐up	Adverse events None mentioned
Notes	2 x 2 tables and summarystatistics Were 2 x 2 tables reported? No If applicable, could 2 x 2 tables be back‐calculated? Yes Were the reported summary statistics confirmed as accurate? No summary diagnostic accuracy statistics were reported, but these were calculated as sensitivity = 84.29, specificity = 76.92, PPV = 90.77 and NPV = 64.52.
Table of Methodological Quality
Item	Authors' judgement	Description
Representative spectrum? All tests	No	The setting was tertiary care and the reference standard (surgery) was more than minimally invasive. Also the sample was selected (all had cuff tears).
Selection criteria described? All tests	Yes
Acceptable reference standard? All tests	Yes	Surgery
Acceptable delay between tests? All tests	No	Most of group 1 had had symptoms for a mean of 30 months before operative treatment.
Partial verification avoided? All tests	Yes	There was an non‐operated control group which was disregarded for the purposes of this review.
Differential verification avoided? All tests	Yes
Incorporation avoided? All tests	Yes
Sufficient description of index tests? All tests	Yes	Probably
Sufficient description of reference test? All tests	No	No procedural details given
Index test results blinded? All tests	No	No statement of blinding and study was retrospective
Reference standard results blinded? All tests	No	There does not appear to have been blinding.
Relevant clinical information? All tests	Yes
Uninterpretable results reported? All tests	Unclear	Study was retrospective
Withdrawals explained? All tests	No	Study was retrospective and withdrawals were unexplained