Table 7

Studies reporting comorbidity status as possible predictor of functional outcome after THA

			Measurement	FU period	Significance
Author, year	Grade	N of pts	tool	(months)	level (p value)	Association	Predictor level of measurement
Quintana, 2009	Moderate	788	WOMAC PF	ST (6 m)	NA	No	Cat (3)
			SF-36 PF		NA		1: 0 comorbidities 2: 1–2 comorbidities 3: >2 comorbidities
Mahomed, 2002	Moderate	103	WOMAC PF+P	ST (6 m)	<0.05	Neg	Cont
							(number of comorbidities)
Moran, 2005	Moderate	749	HHS	ST (6 m)	NA	Neg	Dich
				ST (18 m)			(presence of coronary heart disease and
							previous thromoembolism)
Stevens, 2012	Moderate	653	WOMAC	ST (12 m)	0.01	Neg	Cat (3)
							1: 0 comorbidities 2: 1–2 comorbidities 3: >2 comorbidities
Clement, 2010	High	1312	OHS	ST (12 m)	0.01	Neg	Cont
			SF-12				(number of comorbidities)
Dowsey, 2014	High	835	HHS	ST (12 m)	0.0001	Neg	Cont
							(age-adjusted CCI)
Wang, 2010	Moderate	97	WOMAC	ST (16.8 m)	0.0246	Neg	Dich
							(1: >0 comorbidities 2: 0 comorbidities)
Jones, 2012	Moderate	231	WOMAC	LT (36 m)	0.012	Neg	Dich
							(1; 0 cardiac diseases
							2: >0 cardiac diseases)
Bischoff, 2004	Moderate	922	WOMAC PF	LT (36 m)	NA	Neg	Dich
							(1; >2 chronic diseases
							2. 0–1 chronic diseases)
Smith, 2012	Moderate	1683	HHS	LT (36 m)	<0.001	Neg	Cont
							(ASA grade)
Gandhi, 2010	Low	636	WOMAC	LT (39 m)	<0.05	Neg	Cont
			SF-36 PF				(number of comorbidities)
Nilsdotter, 2003	Low	211	WOMAC PF	LT (42 m)	0.08	No	Dich
							(1: >1 comorbidities 2: 0–1 comorbidities)
Judge, 2013	High	1431	OHS	LT (60 m)	0.001	Neg	Cont
							(number of comorbidities)

All significant results are bold.
BMI, body mass index; Cat, categorical; CCI, Charlson comorbidity index; Cont, continuous; Dich, dichotomous; FU, follow-up; HHS, Harris Hip Score; LEFS, Lower Extremity Functional Scale; LT, long-term; N of pts, number of patients; NA, not applicable; Neg, negative; OHS, Oxford Hip Score; Pos, positive; SF-36 PF, Short Form 36 physical function; ST, short-term; THA, total hip arthroplasty; WOMAC, Western Ontario and Mcmaster Universities Osteoarthritis Index.