Clinical evaluation of avascular necrosis in patients with sickle cell disease: Children's Hospital Oakland Hip Evaluation Scale--a modification of the Harris Hip Score.

OBJECTIVE

To establish the validity and reliability of the Children's Hospital Oakland Hip Evaluation Scale (CHOHES), a modification of the Harris Hip Score, for the evaluation of avascular necrosis (AVN) in sickle cell disease (SCD).

DESIGN

Nonrandomized test-retest.

SETTING

Outpatient clinic.

PARTICIPANTS

Forty patients with SCD and 3 healthy controls participated. Twenty-six SCD patients (15 males, 11 females; mean age, 25 y) had been diagnosed with AVN. This group was compared with 14 SCD patients without AVN and 3 healthy controls (8 males, 9 females; mean age, 16 y).

INTERVENTION

On average, subjects were assessed by 2 physical therapists by using the CHOHES on 3 separate outpatient visits within a 2-week period.

MAIN OUTCOME MEASURES

A mixed model with random effects was constructed to compare patient scores on the CHOHES with disease severity as estimated by Ficat staging on plain radiographs. Correlations between and within physical therapists using the CHOHES were calculated to assess intra- and interrater reliability.

RESULTS

From the random effects model, the CHOHES mean score was 88 for Ficat stage 0, 75 for Ficat stage I or II, and 61 for Ficat stages III or IV (P < .05). Intrarater reliability estimates for the total CHOHES score were very good (r > or = .87) as were interrater reliability estimates (r > or = .90) between therapists who measured hips with a wide range of CHOHES scores.

CONCLUSIONS

The CHOHES appears to be an easy-to-use, valid, and reliable assessment tool and should be considered for use in the routine clinical evaluation of SCD patients with AVN.