PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of eurspinejspringer.comThis journalThis journalToc AlertsSubmit OnlineOpen Choice
 
Eur Spine J. 2009 December; 18(12): 1911–1919.
Published online 2009 August 11. doi:  10.1007/s00586-009-1126-2
PMCID: PMC2899430

Polish adaptation of Bad Sobernheim Stress Questionnaire-Brace and Bad Sobernheim Stress Questionnaire-Deformity

Abstract

Bad Sobernheim Stress Questionnaire-Brace and Bad Sobernheim Stress Questionnaire-Deformity are relatively new tools aimed at facilitating the evaluation of long-term results of therapy in persons with idiopathic scoliosis undergoing conservative treatment. To use these tools properly in Poland, they must be translated into Polish and adapted to the Polish cultural settings. The process of cultural adaptation of the questionnaires was compliant with the guidelines of International Quality of Life Assessment (IQOLA) Project. In the first stage, two independent translators converted the originals into Polish. Stage two, consisted of a comparison of the originals and two translated versions. During that stage, the team of two translators and authors of the project identified differences in those translations and created a combination of the two. In the third stage, two independent translators, who were native speakers of German, translated the adjusted version of the Polish translation into the language of the original document. At the last stage, a commission composed of: specialists in orthopedics, translators, a statistician and a psychologist reviewed all translations and drafted a pre-final version of the questionnaires. Thirty-five adolescent girls with idiopathic scoliosis who were treated with Cheneau brace were subjected to the questionnaire assessment. All patients were treated in an out-patient setting by a specialist in orthopedics at the Chair and Clinic of Orthopedics and Traumatology. Median age of patients was 14.8 SD 1.5, median value of the Cobb’s angle was 27.8° SD 7.4. 48.6% of patients had thoracic scoliosis, 31.4% had thoracolumbar scoliosis, and 20% patients had lumbar scoliosis. Median results obtained by means of the Polish version of BSSQ-Brace and BSSQ-Deformity questionnaires were 17.9 SD 5.0 and 11.3 SD 4.7, respectively. Internal consistency of BSSQ-Brace and BSSQ-Deformity was at the level of 0.80 and 0.87, whereas the value of the absolute stability factor was 0.82 and 0.88. Overall, the Polish versions of the BSSQ-Brace and BSSQ-Deformity Questionnaires are characterized by high values of internal consistency factor and absolute stability factor. Following the process of adaptation, the authors obtained a tool that is instrumental in clinical evaluations and complies with methodological criteria.

Keywords: Idiopathic scoliosis, Quality of life, Cultural adaptation, BSSQ-Brace, BSSQ-Deformity

Introduction

Bad Sobberheim Stress Questionnaire-Deformity (BSSQ-Deformity) and Bad Sobberheim Stress Questionnaire-Brace (BSSQ-Brace) are the new tools to evaluate the stress level in patients with scoliosis due to body deformity and to brace specific stress [5, 6]. BSSQ-Deformity and BSSQ-Brace measure heath-related quality of life. These tools are characterized by high internal consistency, therefore they are reliable tools to evaluate mental condition of patients [5, 6]. These tools were developed in Germany. Progressing European integration does not wipe out cultural differences between neighboring countries. This means that despite their closeness, to use the same tools in an adequate manner, thus assuring the reliability of the results, one needs to implement a process of their linguistic and cultural adaptation specific for each respective country in which the questionnaires are to be used [4]. This adaptation we designed from the German questionnaires BBSQ-Brace or BSSQ-Defomity, corresponds with the commonly accepted social and medical science criteria, that methodologically corrects and evaluates the state of patients’ function.

Our assumption was that if we adapt Bad Sobberheim Stress Questionnaire-Deformity and Bad Sobberheim Stress Questionnaire-Brace to the Polish conditions, we will achieve tools that are equivalent to the original German methods. As a result, we aimed at achieving questionnaires that would help us properly assess long-term outcomes of treatment of idiopathic scoliosis in children with the use of brace in Polish conditions. The process of cross-cultural adaptation of questionnaires was performed accordingly to the guidelines set up by International Quality of Life Assessment (IQOLA). Guidelines for this type of processes in respect to the assessment tools are common for medical, sociological and psychological sciences [4]. Until now, there are no reports published on foreign cross-cultural adaptations of Bad Sobberheim Stress Questionnaire-Deformity and Bad Sobberheim Stress Questionnaire-Brace.

Subjects and methods

Bad Sobberheim Stress Questionnaire-Deformity and Bad Sobberheim Stress Questionnaire-Brace consist of eight questions each. In Bad Sobberheim Stress Questionnaire-Deformity, questions relate to effect of spine deformity on the mood, interactions with the environment and as a result the effect of experienced stress. On the other hand, Bad Sobberheim Stress Questionnaire-Brace focuses on psychological aspects of conservative therapy and assesses the extent to which brace wearing affects mood, distorts social interactions, and in consequence leads to the increase of stress [5, 6].

The score ranges from 0 to 24. The higher the score the less stress, thus 0 signifies greatest stress whereas 24 signifies least stress. The following subdivision of the score values was proposed: 0–8 (strong stress), 9–16 (medium stress), and 17–24 (little stress) [5].

Adaptation process

Translation was performed in compliance with the guidelines of International Quality of Life Assessment (IQOLA) [4] and consisted of a few stages. In the first stage, two independent translators converted the originals into Polish. One of the translators, who had a medical background, was instructed on the whole process of the adaptation. The other translator had no medical background and received no information on the project. Stage two consisted of a comparison of the originals and two translated versions. During that stage, the team of two translators and authors of the project identified differences in those translations and made a combined version. In the third stage—the so called reversed translation—two independent translators, who were native speakers of German, translated a compromised version of the Polish translation into the language of the original document. The translators were not familiar with the original language version. The objective of this stage was to assure equivalence of the two versions and to identify possible mistranslations. At the last stage, a commission composed of: two specialists in orthopedics, translators, a statistician, and a psychologist reviewed all translations. As a result of a consensus, the so called pre-final version was drafted. Following that, persons undergoing assessment filled in Polish versions of BSSQ-Deformity and BSSQ-Brace twice within 2-day-intervals. 35 female patients with idiopathic scoliosis were subjected to the assessment with the use of the questionnaires. All patients were treated with Cheneau brace in an out-patient setting by the same specialist in orthopedics at the Chair and Clinic of Orthopedics and Traumatology. Patients were enrolled to the study when they met the entry criteria, in order of their presentation at the clinic. All patients gave their informed consent prior to their inclusion in the study.

The following entry criteria were applied: female patients at the age of 12–16, who have been wearing the brace for at least 3 months for 12 h a day, with identified median value of the Cobb’s angle between 20 and 40° in thoracic, thoracolumbar or lumbar scoliosis. Median age of patients at the time of filling in the questionnaires was 14 years and 8 months. Patients have been wearing the brace for an average of 16.1 months SD 11.7. Patients have been wearing the brace for 14.9 h SD 3.2 a day on average (Table 1).

Table 1
Description of subjects

On the initiation of treatment, the median value of the Cobb’s angle was 27.8° SD 7.4 (Table 1). 48.6% of patients had thoracic scoliosis, 31.4% had thoracolumbar scoliosis, and 20% patients had lumbar scoliosis. 34.3% of patients had a left curve pattern, and 65.7% of patients had a right curve pattern. Th 6 was an apical vertebra in two patients; Th7 in two patients; Th8 in five patients; Th9 in five patients; Th10 in six patients; Th11 in two patients; Th12 in five patients. L1 was an apical vertebra in six patients; L2 in one, and L3 in one patient.

Statistical analysis

Statistical analysis was performed with the use of Statistica software. Within the descriptive statistics of a given question and a domain, we have conducted analyses, received median scores, measured standard deviations at 95% confidence interval. The distribution of results indicates the number of patients with minimum score (floor effect) and the percentage of patients with highest scores (ceiling score). We have calculated median results for specific questions, percentage distribution of results indicating low, medium, and high stress. Internal consistency of the test was evaluated with Cronbach’s alpha. Absolute time stability index was achieved thanks to test-retest method.

Ethical considerations

The Polish adaptation of the Bad Sobberheim Stress Questionnaire-Deformity and the Bad Sobberheim Stress Questionnaire-Brace as a research project has been approved by the Bioethics Commission.

Results

Lowest and highest scores, median scores, 95% confidence interval obtained by means of BSSQ-Deformity and BSSQ-Brace questionnaires are shown in Table 2. Median score for BSSQ-Deformity was 17.9 SD 5.0 which is interpreted as low stress. Median score BSSQ-Brace was 11.3 SD 4.7 which is interpreted as medium stress. In another test, the median BSSQ-Deformity score was 17.6 SD 4.7, whereas BSSQ-Brace was 10.9 SD 4.6.

Table 2
Distribution of minimal and maximal scores, median scores, 95% confidence interval obtained by means of Polish versions of BSSQ-Deformity and BSSQ-Brace questionnaires

The ceiling effect, i.e., maximal scores (for BSSQ-24) occurred only in the case of BSSQ-Deformity. The first filling applied only to six subjects, 17.1% of all patients. The second filling applied only to four patients, 11.4% of all patients. As far as the floor effect is concerned, i.e., minimal scores (for BSSQ-0) occurred only in the case of the second filling of the BSSQ-Brace and it applies only to one patient which represented 2.9% of all patients.

Table 3 shows the value of Cronbach’s alpha and the absolute time stability factor of the Polish versions of BSSQs assessed with the use of test-retest method in comparison with German results. Table 4 presents interpretation of scores achieved in BSSQ-Brace and BSSQ-Deformity. Most patients (97.1%) experienced low or medium stress caused by body deformity. Only one patient (2.9% of all patients) experienced high stress because of deformity. The results are different in the case of BSSQ-Brace. Here, most of patients (82.9%) experienced high or medium stress. Only 17.1% of patients reported little stress caused by wearing the brace (Table 4).

Table 3
The value of Cronbach’s alpha and absolute stability factor
Table 4
Interpretation of BSSQ-Deformity and Brace-distribution of results within a group

Tables 5 and and66 present results and standard deviations for individual questions. Answers were scored from 1 to 3. Median value for a question in BSSQ-Deformity from 1.9 (question 4) to 2.7 (questions 7 and 8) (Table 6). In case of BSSQ-Brace, these values ranged from 0.9 (questions 2 and 3) to 2.5 (question 8) (Table 7).

Table 5
BSSQ-Deformity-distribution of answers to individual questions
Table 6
BSSQ-Brace-distribution of answers to individual questions
Table 7
Spearman’s rank correlation coefficient (rS) and levels of significance

We have not found any correlation between BSSQ-Deformity, BSSQ-Brace, Cobb’s angle, the degree of the apical translation of center sacral vertical line (CSVL) according to the Harms Study Group [11] and the duration of brace wearing per day and total number of months worn (Table 7). The only statistically significant correlation (p = 0.19) was identified between BSSQ-Brace and the angle of rotation (rs 0.395). It means that the higher the angle of the trunk rotation, the less stress was experienced by wearing a brace. Such results contradict our assumptions.

We also assessed the correlation between the site of the deformity and BSSQ-Deformity and BSSQ-Brace results. Patients who had deformities within the thoracic spine, thoracic-lumbar spine and lumbar spine were in one group. As far as BSSQ-Deformity results are concerned, the difference between the groups is not statistically significant (p = 0.060) (Table 8). As far as BSSQ-Brace results are concerned, the difference between the groups is statistically significant (p = 0.020) (Table 9).

Table 8
Correlation between BSSQ-Deformity and the site of deformity
Table 9
Correlation between BSSQ-Brace and the site of deformity

Discussion

Cultural adaptation of questionnaires drafted in foreign languages as a research project is a methodological standard in social sciences [4]. It was established that this is a necessary process due to incompatibility of socio-cultural and economic conditions in countries where such methods were developed [4]. Such incompatibility leads to the situation in which a regular translation of the original, without considering specific conditions, in a given country, would give a tool that not necessarily reflects the assessed feature in a reliable manner; results may be biased due to region specific factors [4]. The nature of a given culture may render questions, answers or instructions ambiguous and different from the original intent of the author, thus it may lead to the situation in which they could not be used for comparison with the original questions, answers and instructions. Moreover, despite a complex translation process of the original or of a reverse translation back into the original, it may be necessary to assess the reliability of adapted tools. Only upon obtaining values that are approximate to the original, a complex process of adaptation is successful. A questionnaire that was subject to a complex process of adaptation should be a binding counterpart of the original; it allows comparing results in a multicultural context [4].

Analysis of literature suggests that such projects are becoming more and more popular. Recently, there are reports on four adaptations of the English language questionnaire of the Scoliosis Research Society-22 (SRS-22); it has its Spanish, Turkish, Japanese, and Chinese version [1, 3, 9, 13]. Roland–Morris Disability Questionnaire was adapted to three languages—Polish [18], Japanese [17], and German [23]. In case of the Polish adaptation of BSSQ-Brace and BSSQ-Deformity, we had to consider Polish socio-cultural conditions. We need to emphasize participation in the costs of healthcare despite health security insurance and the operation of Health Funds. It means that patients have to pay both for braces and for doctors’ consultations. Sometimes the same scale is adapted twice. The objectives of Bremerich et al. and Scherer et al. were to translate into German and culturally adapt Neck Pain and Disability Scale (NPAD). The said authors proved that both adapted tools are instrumental in the evaluation of German speaking patients [7, 20]. Within the framework of our research on the quality of life of patients with scoliosis, we wanted to adapt to the Polish realities questionnaires that focus on experiencing stress caused by body deformity and wearing the brace (see “Appendix”).

The polish version of BSSQ-Deformity has a lower absolute stability when compared to the original German version, but the value of the Cronbach’s alpha remains high [6]. Cronbach’s alpha and absolute stability factor obtained by means of the Polish version of BSSQ-Brace are slightly lower than the scores obtained by Botens–Helmus et al. [5]; despite that, however, they remain high and exceed the value of 0.8 (values above 0.7 are deemed satisfactory) [24].

As far as the results of BSSQ-Deformity are concerned, vast majority of patients (97.1%) experienced some or little stress. Only one patient (2.9% of all subjects) experienced high stress because of deformity. The results are slightly different in case of the original version of BSSQ-Brace [5]. In this study, 77% of patients experienced severe stress, and only 23% reported little stress [5].

As far as the median scores and standard deviations are concerned for individual questions, median values ranged from 1.9 to 2.7 points for BSSQ-Deformity. In case of BSSQ-Brace, these values ranged from 0.9 to 2.5 points. Similar values were obtained in the original German version of the BSSQ-Brace: from 0.98 (question 6) to 2.54 (question 8) [5]. We have not found any relation between BSSQ-Deformity, BSSQ-Brace, Cobb’s angle, the degree of the apical translation of center sacral vertical line (CSVL), and the duration of brace wearing; the only statistically significant correlation was identified between BSSQ-Brace and the angle of rotation. Such results contradict our assumptions. This may be due to the protective mechanisms of personality, secondary rejection in particular—a mental process that eliminates from consciousness painful experience and fear causing thoughts, events, and feelings [21]. As far as the correlation between the site of the deformity and BSSQ-Deformity and BSSQ-Brace results are concerned, the only statistically significant results were obtained by means of BSSQ-Brace. As we noted earlier (Table 9), more stress was reported by patients with deformities in the thoracic-lumbar spine. Such results contradict the conclusions reached by Botens–Helmus et al. [5]; according to their study, the site of deformity bears no influence on the stress level [5]. Thanks to cultural and language adaptation, we obtained tools that are methodologically correct in assessing the condition of patients who are subject to conservative therapy. Many times when considering mental implications of scoliosis, it has been observed that physical problems and aesthetic issues related to the disease and treatment itself affect the way patients perceive themselves and the type of stress they experience [2, 10, 12, 14, 15, 19, 22].

Danielsson et al. on the other hand studied patients who were treated with braces in a 20 year long observation. It turned out that 34% of those patients felt that their deformity limits their social life mainly due to the difficulties in participating in various activities. Another issue is the problem of appeal. Spinal pain to some extent limits social life [12]. Wickers et al. [22] conclude that patients wearing braces are more prone to rebellious behavior but there is less tension in relations with doctors.

Andersen et al. suggest that patients who initiated conservative treatment over the age of 16 have more difficulties in establishing relations with the opposite sex, when compared to patient who initiated such treatment before the age of 16. About half of the patients reported that they abstained from participating in activities involving spending time with friends. Majority of them, if given a choice, would opt for operative treatment [2]. Matsunaga et al. [16] concluded that to reduce stress in conservatively treated patients and to prevent drop out from therapy, it is important to provide proper information on the type of treatment being applied.

On the basis of studies conducted by Vasiliadis et al. with the use of a new tool—Brace Questionnaire—a correlation between Cobb’s angle and school activity and social engagement of scoliosis patients was found [24]. It was also demonstrated that the value of Cobb’s angle has no influence upon the overall condition of patients, physical condition, emotional, self-esteem, appeal, vitality and pain level [24].

World literature on this topic suggest that scoliosis affects the mental health of patients. Until now, there were no tools that could be methodologically validated and would allow proper assessing of patients with idiopathic scoliosis who were subject to conservative treatment in particular in polish language. Polish adaptation of BSSQ-Brace and BSSQ-Deformity will allow reliable assessment of mental consequences of brace wearing and the influence of the disease on the stress level and impairment of social life. As a result, it will also help to compare the results in the intercultural context.

Conclusions

Our assumption was that if we adapt Bad Sobberheim Stress Questionnaire-Deformity and Bad Sobberheim Stress Questionnaire-Brace to the Polish conditions, we will achieve tools that are equivalent to the original German methods. Our results confirm that the adapted tools are internally highly consistent, reliable, and stable when compared to the original questionnaires. Last but no least, we achieved the tools that will help us properly to assess long-term outcomes of treatment of idiopathic scoliosis in children with the use of a brace in the Polish conditions.

Acknowledgments

We wish to warmly thank Poznan University of Medical Sciences for financing our research project. We declare that the experiments comply with the current polish laws. This project has been given approval from Bioethics Commission.

Appendix

An external file that holds a picture, illustration, etc.
Object name is 586_2009_1126_Figa_HTML.jpg
An external file that holds a picture, illustration, etc.
Object name is 586_2009_1126_Figb_HTML.jpg

Contributor Information

Ewa Misterska, Phone: +48-61-8310360, Fax: +48-61-8334421, lp.pw@1aksretsime.

Maciej Głowacki, Phone: +48-61-8310360, Fax: +48-61-8334421, lp.2o@jeicamikcawolg.

Jerzy Harasymczuk, Phone: +48-61-8475228, Phone: +48-61-8491578, Fax: +48-61-8475228, lp.2o@kuzcmysarah.

References

1. Alaney A, Cil A, Berk H, Acaroglu E, Yazici M, Akcali O, Kosay C, Genc Y. Reliability and validity of adapted Turkish version of scoliosis research society-22 (SRS-22) questionnaire. Spine. 2005;21:2464–2468. doi: 10.1097/01.brs.0000184366.71761.84. [PubMed] [Cross Ref]
2. Andersen FG. Self-concept and coping in adolescents with a physical disability. Issues in mental health. Nursing. 1981;4:257–274. [PubMed]
3. Bago J, Climent J, Ey A, Perez-Grueso F, Izquierdo E. The Spanish version of SRS-22 Patient Questionnaire for idiopathic scoliosis. Spine. 2004;15:1676–1679. doi: 10.1097/01.BRS.0000132306.53942.10. [PubMed] [Cross Ref]
4. Beaton D, Bombardier C, Guillemin F, Ferraz M. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine. 2000;15:3186–3191. doi: 10.1097/00007632-200012150-00014. [PubMed] [Cross Ref]
5. Botens-Helmus C, Klein R, Stephan C. The reliability of the Bad Sobernheim Stress Questionnaire (BSSQbrace) in adolescents with scoliosis during brace treatment. Scoliosis. 2006;1:22. doi: 10.1186/1748-7161-1-22. [PMC free article] [PubMed] [Cross Ref]
6. Botens-Helmus C, Weiss HR, Reichel D, Schanz J, Zimmermann-Gudd S (2006) Reproducibility and criterion validity of the BSSQ-stress Questionnaire for patients with scoliosis. In: Proceedings of the 3rd International Conference on Conservative Management of Spinal Deformities & Scientific meeting of the SOSORT, April 7–8th, Poznan
7. Bremerich FH, Grob D, Dvorak J, Mannion AF (2008) The neck pain and disability scale: cross-cultural adaptation into German and evaluation of its psychometric properties in chronic neck pain and C1-2 fusion patients. Spine 20;33(9):1018–1027 [PubMed]
8. Brzeziński J. Metodologia badań psychologicznych. Warszawa: Wydawnictwo Naukowe PWN; 2007.
9. Cheung K, Senkoylu A, Alanay A, Genc A, Lau S. Reliability and concurent validity of the adapted Chinese version of Scoliosis Research Society-22 (SRS-22) Questionnaire. Spine. 2007;32:1141–1145. doi: 10.1097/01.brs.0000261562.48888.e3. [PubMed] [Cross Ref]
10. Clayson D, Luz-Alterman S, Cataletto MM, Levine DB (1987) Long-term psychological sequelae of surgically versus nonsurgically treated scoliosis. Spine 12:983–986 [PubMed]
11. D’Andrea PL, Betz RR, Lenke GL, Clements HD, Lowe GT, Merola A, Haher T, Harms J, Huss KG, Blanke K, McGlothen S. Do radiographic parameters correlate with clinical outcomes in adolescent idiopathic scoliosis? Spine. 2000;25:1795–1802. doi: 10.1097/00007632-200007150-00010. [PubMed] [Cross Ref]
12. Danielsson AJ, Wiklund I, Pehrsson K. Health-related quality of life in patients with adolescent idiopathic scoliosis: a matched follow-up at least 20 years after treatment with brace or surgery. Eur Spine J. 2001;10:278–288. doi: 10.1007/s005860100309. [PMC free article] [PubMed] [Cross Ref]
13. Hashimoto H, Sase T, Arai Y, Maruyama T, Isobe K, Shouno Y. Validation of Japanese version of the Scoliosis Research Society—22 Patient Questionnaire among Idiopathic Scoliosis patients in Japan. Spine. 2007;4:E141–E146. doi: 10.1097/01.brs.0000255220.47077.33. [PubMed] [Cross Ref]
14. Kinel E, Kotwicki T, Stryla W, Szulc A (2007) First experience with BSSQ Questionnaire. In: Proceedings of the 3rd International Conference on Conservative Management of Spinal Deformities & Scientific meeting of the SOSORT, April 7–8th, Poznan
15. Marcinowicz L, Sienkiewicz J. Assessment of the validity and reliability of the Polish version of the SF-36 questionnaire-preliminary findings. Przegl Lek. 2003;60(Suppl 6):103–106. [PubMed]
16. Matsunaga S, Sakou T, Nozoe S. Psychological effects of brace therapy on patients with idiopathic scoliosis. J Orthop Sci. 1997;2:391–395. doi: 10.1007/BF02488926. [Cross Ref]
17. Nakamura M, Miyamoto K, Shimizu K. Validation of the Roland–Morris Disability Questionnaire for Japanese patients with lumbar spinal diseases. Spine. 2003;28:2414–2418. doi: 10.1097/01.BRS.0000085425.90995.09. [PubMed] [Cross Ref]
18. Opara J, Szary S, Kucharz E. Polish cultural adaptation of the Roland–Morris Questionnaire for evaluation of quality of life in patients with low back pain (Health services research) Spine. 2006;31:2744–2746. doi: 10.1097/01.brs.0000244632.76447.62. [PubMed] [Cross Ref]
19. Sapountzi-Krepia DS, Valavanis J, Panteleakis GP, Zangana DT, Vlachojiannis PC, Sapkas GS (2001) Perceptions of body image, happiness and satisfaction in adolescents wearing a Boston brace for scoliosis treatment. J Adv Nurs 35:683–690 [PubMed]
20. Scherer M, Blozik E, Himmel W, Laptinskaya D, Kochen MM, Herrmann-Lingen C. Psychometric properties of a German version of the neck pain and disability scale. Eur Spine J. 2008;7:922–929. doi: 10.1007/s00586-008-0677-y. [PMC free article] [PubMed] [Cross Ref]
21. Strelau J (red.) (1999) Psychologia. Podręcznik akademicki Tom 1. Gdańskie Wydawnictwo Psychologiczne, Gdańsk
22. Wickers FC, Bunch WH, Barnett PM. Psychological factors in failure to wear the Milwaukee Brace for treatment of Idiopathic Scoliosis. Clin Orthop Relat Res. 1999;1:62–66. [PubMed]
23. Wiesinger G, Nuhr M, Quittan M, Ebenbichler G, Wolfl G, Fialka-Moser V. Cross-cultural adaptation of the Roland–Morris Questionnaire for German-speaking patients with low back pain. Spine. 1999;11:1099–1103. doi: 10.1097/00007632-199906010-00009. [PubMed] [Cross Ref]
24. Vasiliadis E, Grivas TB, Gkoltsiou K. Development and preliminary validation of Brace Questionnaire (BrQ): a new instrument for measuring quality of life of brace treated scoliotics. Scoliosis. 2006;1:7. doi: 10.1186/1748-7161-1-7. [PMC free article] [PubMed] [Cross Ref]

Articles from European Spine Journal are provided here courtesy of Springer-Verlag