RELIABILITY AND VALIDITY OF THE ADAPTED SPANISH VERSION OF THE EARLY ONSET SCOLIOSIS-24 QUESTIONNAIRE

María del Mar Pozo-Balado, PhDHiroko Matsumoto PhD

Michael G Vitale, MDJuan Manuel Praena-Fernández

David M Farrington, MD

INTRODUCTION

• EOSQ-24 is a health-related quality of life disease specific measure for EOS.• It needs to be translated into many languages, while maintaining the original

meaning.

Early Onset Scoliosis Questionnaire (EOSQ-24)

• EOS may negatively impact life expectancy of children.• Even without severe progression, the deformity may interfere with daily life

and might have significant effects on health-related quality of life. • Radiographic parameters are insufficient to evaluate the severity and efficacy

of treatment in these patients.

Early Onset Scoliosis (EOS)

OBJECTIVE

To translate and transculturally adapt the original EOSQ-24 to produce a Spanish version according to internationally published recommendations and to test the reliability and discriminative validity of the Spanish version of EOSQ-24.

PATIENTS AND METHODS I

• Translation and transcultural adaptation of EOSQ into the European Spanish language.

Beaton et al., Spine (2000)• Validity testing of the Spanish version of EOSQ in a cross-sectional study

validation.

Study Design

The EOSQ-24

• Principal disease-specific instrument to be used for studies involving children with EOS.

• Comprised of 24 items in 11 domains.• Item scores ranged between 1 and 5 for all items, with lower scores meaning

higher disability.• Domain scores were calculated as (value of item choice-1)/4 *100 for 1 item

domains and (algebraic mean of items-1)/4*100 for domains composed for more than 1 item, ranging from 0 to 100.

• The 11 domains were also averaged into a summary score called total score, which also may range from 0 to 100.

PATIENTS AND METHODS II

Cross-cultural adaptation and translation process

• Translation• Synthesis• Back Translation• Expert Committee Review• Pretesting

Beaton et al., Spine (2000)

Reliability

• Cronbach’s a and Cronbach’s a if item/domain deleted (0.7-0.95 indicates good internal consistency).

• Item-total correlations (>0.3 indicates good internal consistency).• Inter-item correlations (0.2-0.8 indicates good internal consistency).

Terwee et al, J Clin Epidemiol (2007) Floor and ceiling effects

• Values lower than 30% were considered acceptable.

Kane, Aspen Publishers (2007)

PATIENTS AND METHODS III

Discriminative validity

• Analysis of the relationship between clinical and demographical variables and questionnaire total scores, under the assumption that unfavorable characteristics are associated with poor scores.

• Kruskar Wallis and Bonferroni corrections for multiple comparisons and Mann Whitney-U test for comparisons between two groups.

• Spearman correlations for quantitative variables. • p<0.05 considered statistically significant for all tests.

Characteristic ValueMale sex (%) 22 (50)Age, median months (IQR) 76 [44 - 92]Age at diagnosis, median months (IQR) 39 [16 -69]Age at surgery, median months (IQR) 76 [58 – 91]Cobb angle, median degrees (IQR) 31.1 [24.8 – 45.3]Diagnose (%) Congenital 18 (40.9) Neuromuscular 10 (22.7) Idiopathic 9 (20.5) Syndromic 7 (15.9)Treatment (%) Observation 24 (54.5) Bracing 2 (4.6) Casting 4 (9.1) Surgical 14 (31.8)Ambulation Status (%) Non-ambulatory 8 (18.2) Ambulatory 36 (81.8)

RESULTS I

Demographic and clinical characteristics of 44 children with EOS.

RESULTS II

Demographic and clinical characteristics of 44 children with EOS.

Domains Corrected Item-total Correlation Cronbach’s a if Item DeletedGeneral Health 0.415 0.825Q1 0.496 0.893Q2 0.413 0.895Pain 0.553 0.816Q3 0.502 0.893Q4 0.455 0.894Pulmonary Function 0.472 0.821Q5 0.254 0.898Q6 0.412 0.895Mobility 0.413 0.826Q7 0.435 0.895Physical function 0.607 0.808Q8 0.482 0.893Q9 0.484 0.893Q10 0.661 0.888Daily living 0.675 0.802Q11 0.689 0.887Q12 0.691 0.888Fatigue 0.522 0.816Q13 0.476 0.893Q14 0.474 0.893Emotion 0.592 0.812Q15 0.471 0.893Q16 0.519 0.892Parental Burden 0.655 0.808Q17 0.670 0.890Q18 0.518 0.892Q19 0.550 0.891Q20 0.724 0.887Q21 0.179 0.898Financial Burden 0.353 0.831Q22 0.356 0.896Satisfaction 0.418 0.826Q23 0.472 0.893Q24 0.392 0.895

Cronbach’s a for 24 items = 0.897

Cronbach’s a for domains = 0.832

Good internal consistency for items

and domains.

RESULTS IVRESULTS IIIDomains Mean (SD) Median Missing (n) Missing (%) Floor (%) Ceiling (%) General Health 65.6 62.5 0 11.4Q1 3.50 (1.04) 4 0 0 4.5 15.9Q2 3.79 (0.89) 4 1 2.3 7 23.3Pain 77.9 75.0 0 31.8Q3 4.02 (0.86) 4 1 2.3 0 32.6Q4 4.22 (0.69) 4 3 6.8 0 36.6Pulmonary Function 86.3 100 0 59.1Q5 4.40 (1.18) 5 1 2.3 4.7 74.4Q6 4.50 (0.86) 5 0 0 0 68.2Transfer 90.9 100 0 72.7Q7 4.64 (0.65) 5 0 0 0 72.7Physical function 72.2 83.3 6.8 29.5Q8 3.82 (1.38) 4 0 0 9.2 45.5Q9 4.23 (1.41) 5 0 0 11.4 72.7Q10 3.74 (1.53) 5 2 4.5 11.9 52.4Daily living 56.8 62.5 13.6 25.0Q11 3.05 (1.57) 3 0 0 22.7 27.3Q12 3.50 (1.80) 5 0 0 29.5 52.3Fatigue 73.3 75.0 0 31.8Q13 3.95 (0.94) 4 0 0 0 36.4Q14 3.88 (1.28) 4 1 2.3 4.7 46.5Emotion 76.4 75.0 0 31.8Q15 4.11 (0.87) 4 0 0 0 40.9Q16 4.00 (1.03) 4 0 0 2.3 45.5Parental Burden 61.3 65.0 0 0Q17 2.98 (0.93) 3 0 0 4.5 9.1Q18 3.16 (1.16) 3 0 0 11.4 13.6Q19 3.23 (1.33) 3 0 0 9.1 25.0Q20 3.68 (1.27) 4 0 0 6.8 34.1Q21 4.26 (0.79) 4 1 2.3 0 44.2Financial Burden 75.6 75.0 2.3 45.5Q22 4.02 (1.13) 4 0 0 2.3 45.5Satisfaction 73.3 75.0 0 36.4Q23 3.98 (1.08) 4 1 2.3 0 41.9Q24 3.93 (1.23) 4 0 0 2.3 43.2

Data quality with the Floor and Ceiling Effect of the EOSQ-24.

No floor effects, but ceiling effects observed in some items and domains, probably because…• Young age• Mostly mild curves • More than 50% under

observation

0 20 40 60 80 1000

50

100

150r=-0.473p=0.004

Cobb Angle (degrees)E

OS

Q-2

4 T

ota

l Sco

re

30º > 30º 0

50

100

150

Cobb Angle (degrees)

EO

SQ

-24

To

tal S

core

RESULTS IIRESULTS IV

Discriminative validity of the EOSQ-24 questionnaire: Total Score and Cobb Angle.

Comparison of total scores between EOS patients with Cobb angle >30° and ≤30° were performed using Mann Whitney U-test, and correlations between total scores and Cobb angles were evaluated using a Spearman rank correlation coefficient test .

p=0.001

RESULTS IIRESULTS V

C I N S0

50

100

150

Diagnosis

EO

SQ

-24

To

tal S

core

Discriminative validity of the EOSQ-24 questionnaire: Total Score and Diagnosis

C=Congenital; I= Idiopathic; N= Neurological; S= Syndromic

Comparisons were made by using Kruskal-Wallis test and Mann Whitney U-test *p<0.05

K-W *p=0.006

**

**

CONCLUSIONS

The Spanish version of the EOSQ-24 is reliable and a valid tool for the psychometric assessment of children with EOS, and can be applied in routine clinical practice and for research purposes.