APPENDIX 2.

Results after removing from analysis knees with a history of surgery, bursitis, daily medication use, and injection in last 6 months.

		Knees Without History of Surgery or Injury			Knees Without Bursitis			Knees Without Daily Medication Use			Knees Without History of Injection in Last 6 Mos
		Sn	Sp	LR+	Sn	Sp	LR+	Sn	Sp	LR+	Sn	Sp	LR+
AKP	Any	60	53	1.3	60	51	1.2	62	54	1.3	61	49	1.2
	Isolated	27	78	1.2	27	81	1.4	29	81	1.5	25	80	1.3
Max pain with stairs (up or down)	(≥ min)	72	36	1.1	73	34	1.1	71	33	1.1	75	34	1.1
	(≥ mod)	37	74	1.4	38	73	1.4	37	73	1.4	41	65	1.2
Pain going up stairs	(≥ min)	70	37	1.1	71	35	1.1	69	34	1.0	74	35	1.1
	(≥ mod)	32	79	1.5	33	77	1.4	32	77	1.4	33	71	1.1
Pain going down stairs	(≥ min)	63	44	1.1	64	41	1.1	60	40	1.0	61	40	1.0
	(≥ mod)	28	83	1.6	31	82	1.7	29	85	1.9	32	82	1.8
Absence of pain walking on level ground	(≥ min)	60	39	1.0	58	42	1.0	60	42	1.0	57	41	1.0
	(≥ mod)	95	9	1.0	92	12	1.0	94	10	1.0	93	14	1.1
Any AKP + max pain with stairs	(≥ min)	49	65	1.4	49	63	1.3	50	64	1.4	49	62	1.3
	(≥ mod)	28	84	1.8	28	83	1.6	28	83	1.6	30	80	1.5
Any AKP + absence of pain walking on level ground	(≥ min)	30	74	1.2	29	74	1.1	32	76	1.3	29	72	1.0
	(≥ mod)	57	58	1.4	55	58	1.3	57	60	1.4	55	58	1.3
Isolated AKP + max pain with stairs	(≥ min)	18	88	1.5	20	89	1.8	20	88	1.7	18	87	1.4
	(≥ mod)	9	97	3.0	9	98	4.5	9	96	2.3	8	96	2.0
Isolated AKP + absence of pain walking on level ground	(≥ min)	20	83	1.2	19	85	1.3	21	87	1.6	18	84	1.1
	(≥ mod)	26	79	1.2	26	82	1.4	27	83	1.6	24	80	1.2

AKP: anterior knee pain; max: maximum; min: minimal; mod: moderate.