O R I G I N A L A R T I C L E
Cross-cultural adaptation and validation of the knee and hip health-related quality of life (OAKHQoL) in a Moroccan Arabic-speaking population
Z. Serhier•T. Harzy•S. ELfakir•S. Diouny• K. El Rhazi•M. Bennani Othmani•
L. R. Salmi• C. Nejjari
Received: 15 September 2010 / Accepted: 30 December 2010 / Published online: 19 January 2011 ÓSpringer-Verlag 2011
Abstract
The aim of this study was to adapt the knee and hip osteoarthritis quality of life questionnaire (OAKHQoL) into Moroccan Arabic and to determine its psychometric properties. After translation, back-translation and pretesting, the translated version was submitted to an expert committee.
The psychometric properties were tested on patients with hip or knee osteoarthritis. Internal consistency was tested using Cronbach’s alpha coefficient (a), and the test–retest reli- ability using intraclass correlation coefficients (ICC). Con- struct validity was assessed by examining item-convergent and divergent validity and by comparing the average scores between age groups and walk perimeter groups. The study was conducted on 131 patients (115 with osteoarthritis of the knee and 16 with osteoarthritis of the hip). The ‘‘physical activities’’ (a
=0.93), ‘‘mental health’’ (a
=0.84) and
‘‘pain’’ (a
=0.88) dimensions of the Arabic version were
internally reliable. The ICC were adequate to good; 0.83 for
‘‘physical activities’’, 0.65 for ‘‘mental health’’ and 0.70 for
‘‘pain’’ dimensions. The instrument demonstrated good construct validity; all items exceeded the 0.4 criterion for convergent validity, except items 13 and 41 and most of the correlations between items and their own scale were sig- nificantly higher than their correlations with other scales.
A semantically equivalent translation has been developed with cultural adaptation of OAKHQoL. It is quite reliable and a valid measure of the effect of osteoarthritis on the quality of life on Moroccan patients.
Keywords
Osteoarthritis Quality of life Reliability Validity
Introduction
Osteoarthritis, including gonarthrosis and coxarthrosis, is a major cause of pain and limited mobility, and it impacts health-related quality of life [1–3]. It is one of the most frequent diseases with a prevalence of 12–15% in the general population, rising to 60% over 65 years of age [4,
5]. In Morocco, 17.2% of patients consulting a rheu-matologist had osteoarthritis of limbs [6]. Due to its high prevalence, osteoarthritis is a serious social, health and economic problem. Annual treatment costs of joint diseases in the industrial countries are estimated at 1–2.5% of the gross domestic product [7,
8].The term of quality of life is used to evaluate the general well-being of individuals and societies [9]. Health-related quality of life (HRQoL) is an individual’s satisfaction with domains of life insofar, as they affect or are affected by
‘‘health’’. The assessment of HRQoL enables physicians to take into account the patients’ perception of their own
Z. Serhier (&)M. Bennani OthmaniCasablanca Medical Informatics Laboratory,
Faculty of Medicine, Hassan II University, Casablanca, Morocco e-mail: zserhier@yahoo.fr
T. Harzy
Rheumatology Department, Hassan II University Hospital, Fez, Morocco
S. ELfakirK. El RhaziC. Nejjari
Department of Epidemiology, Clinical Research and Community Health, Fez University, Fez, Morocco
S. Diouny
Department of English, Chouaib Doukkali University, El Jadida, Morocco
L. R. Salmi
Institut de Sante´ Publique d’Epide´miologie et de De´veloppement (ISPED), Universite´ Victor Segalen Bordeaux 2,
Bordeaux, France
DOI 10.1007/s00296-010-1781-y
health status [10,
11]. This kind of information may guidedecision-making in clinical practice [12]. Furthermore, it is usually welcomed by patients who wish to express their concerns. For evaluation of HRQoL, generic rating scales such as the SF-36 [13–15] are used. It has been recom- mended that a generic scale should be used together with a specific instrument [16–18]. Due to epidemiological tran- sition, chronic diseases are increasing in intermediary low income countries like Morocco [19,
20]. Hence, thesecountries need tools to measure the consequences of dis- eases on the quality of life. The Western Ontario and McMaster (WOMAC) osteoarthritis index, which is a functional measure, has been translated and validated in Moroccan Arabic [21]. Beyond physical activities, knee and hip osteoarthritis may have an impact on HRQoL [2].
The Osteoarthritis of the Knee and Hip Quality of Life (OAKHQoL) questionnaire is multidimensional; it could apprehend aspects specifically adapted to knee and hip osteoarthritis patients. The original version of OAKHQoL meets psychometric requirements for validity and reli- ability [22]. Adaptation and validation of this questionnaire in Moroccan Arabic is a good instrument to evaluate HRQoL among Moroccan patients with osteoarthritis and will help to explore the psychometric properties of this questionnaire in a country and a culture different from those where it was developed.
The aims of this study were to translate the original version of OAKHQoL into Moroccan Arabic and to assess the psychometric properties of the translated version.
Methods
Translation and cultural adaptation of the OAKHQoL The published guidelines were followed for the process of cross-cultural adaptation [23]. Two different translators independently translated the questionnaire from French into Moroccan Arabic, and a consensus version was obtained by discussion of translators under supervision of the main author. This Arabic version was back-translated into French by two other translators totally blind to the original French version. An expert committee, composed of a rheumatologist, two methodologists and four transla- tors (forward and back translators), reviewed all transla- tions and developed the prefinal version. A final Arabic version was generated after a pre-testing the prefinal ver- sion on a group of five patients.
Participants and data collection
The validation population consisted of patients recruited in two rheumatology consultations (UHC Hassan II in Fez
and Moulay Ismail Hospital in Meknes) and two rehabili- tation centres (Ibn AL Khatib Hospital in Fez and Riyad Alkastani in Meknes), from February 1st to May 31st, 2008. The two sites of the study are located in central north Morocco. Subjects were required to have osteoarthritis according to American College of Rheumatology criteria [24,
25], to speak Moroccan Arabic and to be free of anyother disabling disorder. They completed twice the Arabic version of the OAKHQoL questionnaire: one was self- administered and the other administered by an interviewer.
In illiterate patients, the two questionnaires were admin- istered by two different interviewers. The order of inter- viewers and administration/self-administration were randomly defined.
All participants were also asked to fill in the EuroQol-5 Dimension (EQ-5D) and the WOMAC questionnaires and provided socio-demographic, clinical data and a measure of pain on a visual analogical scale (VAS). To assess repro- ducibility, a third OAKHQoL questionnaire was adminis- tered or self-administered three to 10 days later.
Questionnaires
The OAKHQoLThe OAKHQoL is a 43-item questionnaire composed of five dimensions (physical activities, pain, mental health, social activities and social support) and three independent items. Patients were asked to report the impact of osteo- arthritis on their quality of life over the last 4 weeks. Each item was scored on a scale from 1 to 10. Scores were obtained by computing the means of the item scores in each subscale. Scores were normalized to a 0 (worst possible quality of life) to 100 (best possible quality of life) scale.
VAS pain
Pain was rated using a scale of 0–100 with 0 indicates no pain and 100 very intense pain. Patients indicated the intensity of pain they were feeling on a graduated line.
The EQ-5D
The EQ-5D is a standardized instrument to measure health
outcome. It provides a simple descriptive profile and a
single index value of health status ranging from 0 (death) to
1 (perfect health). EQ-5D consists of five questions cov-
ering the dimensions of mobility, self-care, usual activities,
pain/discomfort and anxiety/depression, each with three
levels of response [26]. The psychometric properties of the
Moroccan version were adequate. The Kappa coefficient
ranged from 0.49 to 0.92, the intraclass correlation coef-
ficient (ICC) was 0.92, and good correlations between
EQ-5D et SF-36 dimensions were noted (r
=0.53–0.85) (Khoudri I et al.
36th congress of the SRLF. Paris 2008).The WOMAC
The WOMAC osteoarthritis index is a disease-specific self- report questionnaire assessing three dimensions: pain (five questions), stiffness (two questions) and physical disability (17 questions) in patients with osteoarthritis of either the hip or the knee [27]. The Likert version of the WOMAC was rated on an ordinal scale of 0–4, with lower scores indicating lower levels of symptoms or physical disability.
Each subscale was summated to a maximum score (worst quality of life) of 20, 8 and 68, respectively. There was also an index score or global score, which was calculated by summating the scores for the three subscales. The Moroc- can version of the WOMAC showed good reliability, with ICC values of the three dimensions: pain, stiffness and physical function being 0.80, 0.77 and 0.89, respectively.
There were statistically significant correlations with all WOMAC subscale and VAS of pain and between physical function subscale and VAS handicap [21].
Statistical methods
The sample size was determined according to Streiner curve [28]. For an ICC of 0.70 and a precision of
±0.10, asample of 120 patients was required. Scores for each of the five dimensions of the OAKHQoL, EQ-5D and WOMAC were calculated. The percentage of missing data was tab- ulated for each item; less than 5% was considered acceptable [10,
28,29], but a higher proportion of missingdata was accepted for items considered more intrusive. The frequency distributions of individual items were examined to detect ceiling or floor effects. There were ceiling or floor effects when more than the third of patients answered by the extreme modalities [30].
Internal-consistency reliability of the multi-item scales was assessed by Cronbach’s
acoefficient. A value of 0.70 or greater was considered adequate [31,
32]. Inter-rater andintra-rater reliabilities were assessed by the ICC, derived from a two-way analysis of variance in a random effect model. Content validity and face validity were based on judgement of three rheumatologists, different from the one involved in the development process.
Construct validity was obtained by comparing the average scores between age groups studied (
\60, 60–70,
[70 years old) and walk perimeter (50–100, 100–500,
[500 m), and by testing item-convergent validity (item- scale correlations should be
[0.40 [33–35]) and divergent validity (the correlation of each item with its hypothesized scale should be significantly higher than correlations of the same item with other scales [35,
36]). For divergentvalidity, a scaling error for an item was obtained when the correlation between an item and its own scale was not significantly higher than its correlation with any other scale. Construct validity was also tested by examining the associations between the scores of each domain, EQ-5D score and scores of WOMAC, using Spearman’s correla- tion coefficient.
All statistical analyses were performed using SPSS 16.0
Ò.
Results
Translation and content validity
After reviewing the translation and back-translation of OAKHQoL, and test of the pre-final version on five patients, minor modifications were implemented to obtain the final Arabic version, for example an explanation was added between brackets for item 16 ‘‘Been afraid of becoming an invalid’’ (been afraid to be unable to do anything). The back-translated version was very similar to the original. Three rheumatologists considered the instru- ment appropriate to measure HRQoL in patients with osteoarthritis of the knee and hip and judged that the questionnaire had good content and face validities.
Sample socio-demographic and clinical characteristics, and descriptive statistics of items and scores
Out of the 135 patients invited to participate in the study, 131 accepted (response rate 97%), 115 had osteoarthritis of the knee and 16 osteoarthritis of the hip. The sample was predominantly female (89%) with a mean age of 56 years (SD 10 years). Sixty-three per cent of patients were illit- erate (Table
1).The pain intensity measured on VAS was moderate with a mean of 46.4 (SD 24.9), and the mean score of WOMAC total scale was 44 (SD 18) (Table
2).On average, missing data rate for items was 2.1%; it ranged from 0% for 22 items to 52% for item 23 ‘‘restricted in sexual life’’. The items that had more than 5% of missing responses were item 13 ‘‘need to spare oneself’’, item 22
‘‘hindered in life with partner’’ and item 23 ‘‘restricted in sexual life’’ (Table
3).Relatively high ceiling or floor effects were observed for item 3 ‘‘carrying heavy things’’, item 13 ‘‘Need to spare oneself’’, item 17 ‘‘Been afraid of becoming an invalid’’, item 18 ‘‘Embarrassed when people see me’’, item 21
‘‘Hindered in family life’’, item 22 ‘‘Hindered in life with
partner’’, item 23 ‘‘restricted in sexual life’’, item 25 ‘‘Need
a stick to walk’’, item 28 ‘‘Need help’’, item 30 ‘‘Able to
plan for the future’’, item 37 ‘‘Feel being a burden to close
relatives’’, item 39 ‘‘Talking about arthritis problems’’, item 41 ‘‘Feel embarrassed to ask for help’’, item 42 ‘‘Feel support from people close to me’’, item 43 ‘‘Feel support from people around’’ (Table
3).Score distributions are shown in Table
4. The meanscores for different subscales ranged from 42.5 (Physical activities) to 60.8 (social functioning).
Reliability and construct validity
Internal consistency (Table
4) was high for the total scale(a
=0.89), and Cronbach’s alpha coefficients for the separate dimensions ranged from alpha
=0.50 (social support) to alpha
=0.93 (physical activities).
Inter-rater reliability was substantial for physical activ- ities, mental health and pain scales (Table
4). Intra-raterreliability was excellent for physical activities and mod- erate for social support, pain and mental health scales.
There was a significant difference in mean scores for the physical activities and social functioning between the age groups (Table
5); patients younger than 60 years had sig-nificantly higher physical activities (P
=0.03) and social functioning (P
=0.002) scores than older persons. The physical activities (P
\0.0001), mental health (P
=0.014) and pain scores (P
=0.001) were statistically different between the walk perimeter classes. Physical activities and pain scores decreased with the decrease of walk perimeter;
mental health score was higher in patients with a walk perimeter
[500 m. No difference was noted between hip and knee osteoarthritis and between genders.
All items exceeded the 0.4 criterion for convergent validity on all scales, except items 13 ‘‘need to spare oneself’’ (physical activity sub-scale) and 41 ‘‘Feel embarrassed to ask for help’’ (Mental health sub-scale).
Most of the correlations of items with their own scales were significantly higher than their correlations with other scales (Table
6).The physical activity scale had good correlations with the WOMAC and the EQ-5D scales (Table
7). VAS painwas moderately correlated with the OAKHQoL pain scale.
The social dimensions specific to OAKHQoL were weakly correlated with the WOMAC dimensions, EQ-5D and VAS pain.
Discussion
The process of translation and cross-cultural adaptation was carefully conducted following the published criteria [23,
37] and resulted in a back-translated version that wasvery similar to the original. The Moroccan Arabic version of the OAKHQoL exhibited acceptable validity and reli- ability. Inter-rater and intra-rater reliability were confirmed by the ICC for the subscales. Cronbach’s alpha coefficient was 0.89 for the total scale, indicating adequate internal reliability. The coefficient ranged from 0.50 for ‘‘social support’’ to 0.93 for ‘‘physical activities’’. Internal con- sistency was better in the original version, but the lowest coefficient was observed for ‘‘Social support’’ (0.72) [38], and the Cronbach’s alpha coefficients for ‘‘physical activ- ities’’ (0.96), ‘‘Mental health’’ (0.93) and ‘‘pain’’ (0.90)
Table 1 Socio-demographic and clinical characteristics of osteoar-thritis patients (n=131)
Numbers Percentage
Centre
Fez 86 65.6
Meknes 45 34.4
Sex
Female 117 89.3
Marital status
Single 8 6.3
Married 90 70.9
Divorced or widowed 29 22.9
Residence
Urban 122 94.6
Education
Illiterate 80 63.0
Primary 22 17.3
Secondary 18 14.2
University 7 5.5
Employment status
Employed 19 14.7
Osteo-arthritis joint
Knee 115 87.8
Hip 16 12.2
Table 2 Measure of pain and mean scores of EQ-5D and WOMAC scale in osteoarthritis patients
Mean Standard deviation Pain intensity
VAS (range 0–100) 46.4 24.9
EQ-5D
(range 0–1) 0.4 0.3
WOMAC
Total scale (range 0–96) 43.9 17.8
Pain (range 0–20) 9.59 4.34
Stiffness (range 0–8) 2.53 2.03
Physical function (range 0–68) 31.85 13.16
Table 3 Floor, ceiling effect and missing data of the items of the OAKHQoL
Abbreviated item content of OAKHQoL 2.3 Floor effecta(%) Ceiling effectb(%) Missing datan(%)
Q1. Walking 4.6 11.5 0 (0.0)
Q2. Bending or straightening 6.9 11.5 0 (0.0)
Q3. Carrying heavy things 4.6 37.4 0 (0.0)
Q4. Going down stairs 6.1 20.6 0 (0.0)
Q5. Climbing stairs 4.6 20.6 0 (0.0)
Q6. Taking bath 20.6 13.7 0 (0.0)
Q7. Dressing 19.1 9.2 0 (0.0)
Q8. Cutting toe-nails 10.7 23.7 0 (0.0)
Q9. Getting moving after staying in the same position 5.3 13.0 0 (0.0)
Q10. Getting in and out a car 12.2 9.2 0 (0.0)
Q11. Using public transport 14.2 21.2 1 (0.8)
Q12. Hindered in professional activity 14.3 14.3 0 (0.0)
Q13. Need to spare oneself 2.6 47.0 16 (12.2)
Q14. Take longer doing things 7.1 7.9 4 (3.1)
Q15. Feel depressed because of pain 8.5 17.8 2 (1.5)
Q16. Been afraid of being dependent on others 21.7 22.5 2 (1.5)
Q17. Been afraid of becoming an invalid 10.0 36.2 1 (0.8)
Q18. Embarrassed when people see me 65.6 7.2 6 (4.6)
Q19. Worry 10.7 13.7 0 (0.0)
Q20. Feel depressed 16.8 10.7 0 (0.0)
Q21. Hindered in family life 35.1 11.5 0 (0.0)
Q22. Hindered in life with partner 53.8 14.3 7 (7.8)*
Q23. Restricted in sexual life 50.0 13.0 47 (52.2)*
Q24. Staying for a long time in the same position 9.5 16.7 5 (3.8)
Q25. Need a stick to walk 71.8 11.5 0 (0.0)
Q26. Frequency of pain 3.1 32.6 2 (1.5)
Q27. Intensity of pain 3.1 14.5 0 (0.0)
Q28. Need help 7.1 35.4 4 (3.1)
Q29. Feel older than my years 23.4 18.8 3 (2.3)
Q30. Able to plan for the future 12.7 33.3 5 (3.8)
Q31. Going out whenever would like 17.6 30.5 0 (0.0)
Q32. Have friends in whenever would like 13.3 29.7 3 (2.3)
Q33. Having difficulties getting to sleep because of pain 27.5 15.3 0 (0.0)
Q34. Wake up at night because of pain 26.7 15.3 0 (0.0)
Q35. Wonder what is going to happen 20.6 25.2 0 (0.0)
Q36. Feel aggressive and irritable 16.8 12.2 0 (0.0)
Q37. Feel being a burden to close relatives 66.9 7.7 1 (0.8)
Q38. Worried about the side-effects of treatment 29.1 16.5 0 (0.0)
Q39. Talking about arthritis problems 15.3 44.3 0 (0.0)
Q40. Feel others understand arthritis problems 14.0 29.5 2 (1.5)
Q41. Feel embarrassed to ask for help 40.3 27.1 2 (1.5)
Q42. Feel support from people close to me 6.9 56.5 0 (0.0)
Q43. Feel support from people around 44.6 23.1 1 (0.8)
* Percentage is estimated with married persons in the denominator
a Percentage of the lowest modality
b Percentage of the highest modality
were slightly similar to those obtained in this study 0.93, 0.84 and 0.88, respectively. The ICC found in this study were comparable to those reported in the French one [38].
Three items had more than 5% of missing responses, item 13 ‘‘need to spare oneself’’ (12.2%), item 22 ‘‘hin- dered in life with partner’’ (7.8%) and item 23 ‘‘restricted
Table 4 Mean scores, Cronbach’s alpha coefficient and intraclass correlation coefficients (ICC) for the Moroccan version of the OAKHQoL questionnaire scalesScales (number of items) Scores mean (SD) Cronbach’sa ICC (95% CI)
Inter-rater (n=128) Intra-rater (n=41)
Physical activities (16) 42.5 (21.6) 0.93 0.90 (0.85–0.93) 0.83 (0.71–0.91)
Mental health (13) 52.8 (20.7) 0.84 0.83 (0.76–0.88) 0.65 (0.43–0.79)
Pain (4) 45.0 (27.8) 0.88 0.81 (0.73–0.86) 0.70 (0.50–0.83)
Social support (4) 59.4 (24.0) 0.50 0.64 (0.52–0.73) 0.71 (0.51–1.83)
Social functioning (3) 60.8 (27.5) 0.60 0.58 (0.44–0.68) 0.54 (0.28–0.73)
Table 5 Construct validity of the OAKHQoL questionnaire
Physical activities Mental health Pain Social support Social functioning
Mean SD P Mean SD P Mean SD P Mean SD P Mean SD P
Age (years) 0.028 0.998 0.132 0.716 <1023
\60 46.6 19.9 52.6 20.6 48.8 27.2 60.5 23.6 66.8 24.7
[60–70] 38.2 24.4 52.9 20.3 40.0 30.3 59.0 26.6 56.0 30.4
C70 33.3 20.2 52.6 23.9 36.4 24.3 55.2 22.3 38.8 21.9
Walk <1023 0.014 0.001 0.73 0.47
Perimeter (m)
B50 27.5 14.9 48.4 21.5 28.2 24.9 63.5 19.6 52.4 32.4
[50–100] 37.8 17.5 41.9 25.6 33.3 28.4 61.7 27.9 66.7 31.8
[100–500] 40.1 20.0 47.8 18.7 40.9 25.6 60.6 24.5 60.6 26.8
[500 52.7 21.6 59.7 19.9 56.1 27.9 56.8 23.8 64.2 28.0
Sex 0.9 0.14 0.42 0.45 0.96
Female 42.6 21.7 52.0 20.2 44.4 28.3 60.0 24.4 60.8 27.5
Male 43.4 21.1 60.8 24.6 51.0 23.9 54.6 21.0 60.4 29.8
Joint 0.75 0.61 0.93 0.35 0.49
Knee 43.0 22.0 53.0 21.6 45.0 27.9 60.2 24.5 61.1 28.0
Hip 41.1 19.4 50.8 14.5 44.3 29.1 54.2 21.1 56.0 24.1
Pvalue in bold indicates that differences were statistically significant SDStandard deviation
PSignificance level
Table 6 Multitrait scaling analysis of the OAKHQoL questionnaire (Moroccan Arabic version)
Scale Item-own scale
correlation
Item-convergent validity scaling errora
Item-other scale correlation
Divergent validity scaling errorb
Physical activities 0.32–0.83 1/16 0.00–0.67 11/64
Mental health 0.30–0.73 1/13 0.00–0.57 9/52
Pain 0.80–0.91 0/4 0.00–0.65 0/16
Social support 0.52–0.74 0/4 0.02–0.27 0/16
Social functioning 0.66–0.82 0/3 0.03–0.32 0/12
a Item convergent validity scaling error=number of item-scale correlations lower than 0.40/total number of item-scale correlations
b Divergent validity scaling error=number of correlations of items with own scales not significantly higher than correlations with other scales/
total number of correlations
in sexual life’’ (52.2%); the proportions of missing data for these items in the original version were 3.0, 5.2 and 14.8%.
The high proportion of missing data for item 13 showed that this item was not clear, concerning item 22 and item 23, missing data were observed because these items are intrusive especially in a country where speaking about sexual life is a taboo. Ceiling effects were observed for seven items; three of them belonged to the physical activities subscale. The extreme response corresponded to the worst quality of life. Item 17 ‘‘been afraid of becoming an invalid’’ of mental health subscale. This result could be explained by the fact that osteoarthritis is known to be a risk factor of disability and limitation in daily activities [1,
39, 40]. Two items were a part of social support sub-scale; the same effect was noted for these items in Rat et al.’s study (item 39 and item 42) [22]. Floor effects were observed for eight items; the same effect was observed for five items in Rat et al.’s [33] study (item 18, item 21, item 22, item 23 and item 25). The three remaining items were item 37
‘‘feel being a burden to close relatives’’, item 41 ‘‘feel embarrassed to ask for help’’ in the Mental health subscale and item 43 ‘‘Feel support from people around’’ in the social support subscale; in Rat et al. study, there was a ceiling effect for item 43, may be there was difference in the meaning of
‘‘support’’ in the two countries, Moroccan patients could attribute a financial dimension to the meaning while French patient could attribute to it a moral support.
The lowest scores, corresponding to reduced quality of life, were observed for ‘‘physical activities’’ and ‘‘pain’’
sub-scales; this result was also reported in French patients [38]. Similar results were reported in Iranian patients with osteoarthritis of the knee; the worst scores were observed for ‘‘walking and bending’’ and ‘‘arthritis pain’’ of the arthritis impact measurement scales 2 (AIMS2) [41]. The
‘‘mental health’’ and ‘‘social support’’ scores were higher in Rat et al.’s study (61.2 and 73.7, respectively); this dif- ference may be attributed, in part, to the difference in educational and socio-economic level between the two
countries. The majority of Moroccan patients were illiter- ate, they could misunderstand the nature of their disease and feel embarrassed when talking about it, and the social support could have a financial dimension for these patients;
most of them were unemployed and did not have a social security, so they often need a financial support, from their families, for the management of their disease. Compared to Moroccan patients, social support could have another meaning for French patients.
Physical activities and social functioning scores varied with age; this variation was noted in the original version [38]. Absence of difference in scores between genders could be attributed to the small size of men sample (inadequate power).
Construct validity was also assessed by correlating OAKHQoL scale scores with the corresponding WOMAC scales, EQ-5D and pain VAS, the most common concurrent scale used in validation studies is the SF36, it was not used because it includes 36 items, it could be hard for patients to complete the OAKHQoL questionnaire twice and the SF36, the EQ-5D which is a short scale was preferred, especially since administration of questionnaire needs more time than auto-administration. The WOMAC scales were validated in Moroccan patients with osteoarthritis of the knee, the EQ-5D was validated in patients in intensive care medicine, but results have not been published yet in indexed review. The pain VAS scale was not highly cor- related (-0.41) to the OAKHQoL pain scale because the OAKHQoL measures pain during the previous 4 weeks in different situations and the pain VAS measures pain during the interview (patients could have no pain at the moment of the interview, but have suffered from pain in the last 4 weeks). Modest correlation (-0.44) between pain VAS and OAKHQoL pain scale was also reported in Rat et al.’s [38] study. As expected, the social dimensions specific to OAKQQoL were weakly correlated with the WOMAC dimensions and EQ-5D since these questionnaires do not require social support and social functioning.
Table 7 Correlations between the scales of the OAKHQoL and the scales of the WOMAC OAKHQoL
Physical activities Mental health Pain Social support Social functioning
WOMAC (Global score) -0.82** -0.46** -0.64** -0.04 -0.25*
Pain -0.71** -0.47** -0.67** -0.06 -0.25**
Stiffness -0.62** -0.39** -0.56** 0.06 -0.23*
Physical function -0.78** -0.41** -0.56** -0.10 -0.23*
EQ-5D 0.70** 0.38** 0.59** -0.14 0.20*
VAS pain -0.29** -0.22** -0.41** -0.11 -0.17
EQ-5D and VAS pain
** Correlation is significant at the 0.01 level
* Correlation is significant at the 0.05 level
Most patients had an interviewer-administered ques- tionnaire, because of the high level of illiteracy. Unlike northern countries, the questionnaire could not be used as an auto-administered questionnaire except for a minority of the Moroccan population.
This study had some limitations; there was probably a selection bias, most of patients recruited were women and the sensitivity to change was not performed. It is recom- mended that additional studies be carried out with patients under active treatment in order to document it.
Although the Arabic language is a commonly spoken across the country, there are some regions, where people speak ‘‘Tarifit’’, ‘‘Tamazight’’ and ‘‘Tachelhit’’. In these areas, Arabic is rarely spoken. Therefore, further validation should be specifically performed in these regions because inclusion of these patient groups in local or national clin- ical studies is essential.
Conclusion
The OAKHQoL was adapted for the first time into Arabic language. This cross-cultural adaptation will permit to use this questionnaire in cohort studies measuring quality of life in patients with lower limb osteoarthritis, and trials of medical or rehabilitative interventions in Morocco.
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