Shoulder pain in primary care: diagnostic accuracy of clinical examination tests for non-traumatic acromioclavicular joint pain

Table 6 Diagnostic accuracy of combinations of history and physical examination variables for a positive response to acromioclavicular joint diagnostic block

Number of positive clinical tests^a	Cell counts				Diagnostic accuracy
	TP	FN	FP	TN	Sensitivity (95% CI)	Specificity (95% CI)	PPV (95% CI)	NPV (95% CI)	LR+ (95% CI)	LR- (95% CI)	OR (95% CI)
One or more	22	0	116	9	1.00 (0.85, 1.00)	0.07 (0.04, 0.13)	0.16 (0.11, 0.23)	1.00 (0.70, 1.00)	1.08 (1.07, 1.15)	0.00 (0.00, 2.15)	0.84 (0.78, 0.90)
Two or more	21	1	61	70	0.96 (0.78, 0.99)	0.53 (0.45, 0.62)	0.26 (0.17, 0.36)	0.99 (0.92, 1.00)	2.05 (1.61, 2.52)	0.09 (0.02, 0.41)	24.10*** (3.15, 184.45)
Three or more	12	10	22	109	0.55 (0.35, 0.73)	0.83 (0.76, 0.89)	0.35 (0.22, 0.52)	0.92 (0.85, 0.95)	3.25 (1.83, 5.40)	0.55 (0.32, 0.79)	5.95*** (2.29, 15.47)
Four or more	5	17	6	125	0.23 (0.10, 0.43)	0.95 (0.90, 0.98)	0.46 (0.21, 0.72)	0.88 (0.82, 0.92)	4.98 (1.69, 13.84)	0.81 (0.59, 0.95)	6.13** (1.69, 22.27)
Five or more	0	22	0	131	†	†	†	†	†	†	†

Abbreviations. TP, true positives; FN, false negatives; FP, false positives; TN, true negatives; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value; LR+, positive likelihood ratio; LR-, negative likelihood ratio; OR, odds ratio.
Note: Cell counts do not total 153 in some cases due to missing data.
^aAny combination of the following positive tests: onset of pain due to repetitive activity; no pain referral below elbow; ACJ thickened or swollen; typical symptoms are not provoked during PROM GHJ abduction or PROM external rotation (90° abduction).
† Invalid calculation (no participants reported five positive clinical tests).
** P≤0.01; *** P≤0.001.