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Ngwira, Lucky-Gift (2022) Childhood health-related quality of life in context of economic evaluation in Malawi, Thesis (Doctoral), Liverpool School of Tropical Medicine.
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L Ngwira - Thesis (Final).pdf - Accepted Version Download (21MB) | Preview |
Abstract
Background & aims:
Preference-based measurements (instruments) of childhood health-related quality of life (HRQoL) in sub-Saharan Africa (sSA) are limited. This thesis set out: i) to identify existing childhood preference-based HRQoL instruments; ii) to explore how the existing instruments
are adapted for use in sSA and; iii) to establish if the adaptation process aligns with local health perceptions in Malawi.
Methods:
Step 1: Systematic review and selection of childhood preference-based HRQoL instruments This step involved: i) a literature review to identify existing childhood preference-based HRQoL measures, and their use in sSA settings; and ii) assessing identified instruments in terms of their psychometric properties and adherence to utility theory to inform the selection of measures for cross-cultural adaptation in Malawi.
Step2: Cross-cultural adaptation of childhood preference-based HRQoL instruments The adaptation process included the following two stages.
i) Translation: Two independent translators forward and backward translated selected instruments (EQ-5DY, EQ-5D-Y-5L, PedsQL™ 4.0 child self-report, and PedsQL™ 4.0 teen self-report) into Chichewa language for Malawi. The translated versions were piloted (cognitive interviews) in a sample of participants (n=38), aged 8-17years from the main referral hospital and primary and secondary schools within Blantyre city, the commercial capital of Malawi.
ii) Cognitive interviews process:
a) Self completion of the questionnaire
For the EQ-5D-Y-5L only, a card exercise was employed to assess the correct hierarchical ranking of response options. All the Chichewa translated instruments were administered to different sets of participants for self-completion. If necessary, children who struggled to
understand instruction for self-completion of the questionnaires were given assistance but not on how to respond to them.
b) Cognitive interviews
Each child participating in the interviews then took part in a one-to-one interview about their understanding of the questionnaire. The interviews were open ended, and participants were asked to comment on how they understood each question and response options. Following
piloting and making necessary changes, pre-final Chichewa versions were sent to developers for approval.
Step 3: Psychometric validation
The approved Chichewa versions were administered to a larger sample (n=298, age 8-17 years) consisting of healthy (n=95) and sick (chronic and acute, n=194) children to assess psychometric performance. The EQ-5D-Y and EQ-5D-Y-5L have five dimensions each with three and five response options respectively. The PedsQL™ 4.0 has 23 items and five response options each. The EQ-5D-Y and EQ-5D-Y-5L scores were generated in two different ways. HRQoL sum scores were generated by adding numeric values of response levels and utility scores were generated using USA utility values to evaluate psychometric performance and utility performance (empirical validity) respectively. The PedsQL™ 4.0 scores were generated following an algorithm provided by the instrument developers. The instruments performance were then assessed using standardized psychometric criteria: item performance (missing data >5%); internal consistency reliability (Cronbach a ³0.7); and validity (convergent of EQ-5DY sum scores and PedsQL™ 4.0 scores >0.4; discriminant: no association between HRQoL
scores with gender & grade; known groups between healthy and sick groups: effect size >0.5). Additionally, since the EQ-5D-Y and EQ-5D-Y-5L are utility instruments, they were assessed for empirical validity (relative efficiency of the EQ-5D-Y-5L relative to the EQ-5D-Y, where
>1 means the former performing better than the latter). Content validity was later evaluated by firstly developing a conceptual framework for health from four focus group discussions (FGDs) composed of 6-12 participants, aged 8-17 years. The framework was conceptualized using axial and selective coding FGDs to generate main concepts which were considered important by children and adolescents in a Malawian setting. The concepts from the model were compared
against those of the existing EQ-5D-Y dimensions to assess if the EQ-5D-Y contains all the relevant dimensions that children and adolescent consider important in this setting.
Results:
Ten preference-based HRQoL instruments were identified and none of these had been developed in low- and/or middle- income countries. Of these, only two (HUI3 and EQ-5D-Y had been used in a sSA setting. : i) EQ-5D-Y (preference-based), and ii) PedsQL™ 4.0 selfreport
(non preference-based) were selected for cross-cultural adaptation into Chichewa and subsequently psychometrically validated in a Malawian setting.
i) Translation:
There were several conceptual and linguistic problems identified from the translation process. Most of these were identified and resolved by translators during the consensus process. However, translation issues such as those referring to ‘life’, ‘health’, and ‘healthy’ were
problematic. Some translation issues including those pertaining to qualifiers for responses and dimension equivalence were only resolved during cognitive interviews.
ii) Cognitive interviews process:
a) Self-completion of the questionnaires
Children, <12 years, struggled to self-complete questionnaire without interviewer assistance.
b) Cognitive interviews on conceptual issues and questionnaire
Children related the EQ-5D-Y ‘looking after oneself’ dimension to lack of provision such as soap instead of functional ability. ‘Kusamba’ in PedsQL™ 4.0 translated ‘to bath’ was found to imply a menstrual cycle and the translation was subsequently revised. Four rounds of card
ranking exercise were necessary to establish appropriate EQ-5D-Y-5L hierarchical ordering.
iii) Psychometric validation:
There was little problem with missing data except in children aged 8-12 years. The Cronbach assessment of internal consistency reliability was acceptable and above the threshold (a>0.7) for all instruments. The correlation of EQ-5D-Y (EQ-5D-Y-5L) sum scores and PedsQL™ 4.0
overall scores was >0.4, providing evidence of convergent validity; but the correlation between some of the EQ-5D-Y dimensions and PedsQL™ 4.0 self-report sub-scales was mixed. There was no association between HRQoL scores with gender and age but the association with school grade (p<0.05) showed lack of discriminant validity. For empirical validity, the EQ-5D-Y-5L was 31%-91% less efficient than the EQ-5D-Y at detecting differences in health status using external measures. A new conceptual framework describing health for Malawi children/young people was developed with seven concepts. Some concepts like ‘God-given ‘and ‘acceptanceof illness’ have rarely been included in generic health instruments. Only two concepts in the model were at the same level as two EQ-5D-Y dimensions.
Discussion and conclusion:
Health, life and healthy were complex terms to translate, and even with help from cognitive interviews these were found to be problematic. The cognitive interviews were instrumental in isolating translation problems and appropriate hierarchical ordering. The psychometric
findings demonstrate that the Chichewa (Malawi) PedsQL™ 4.0 child self-report and PedsQL™ 4.0 teen self-report established reliability, but evidence of their validity was mixed. While the PedsQL™ 4.0 child self-report met most psychometric criteria, the missing data and lack of known-groups validity means this should be used with caution in younger children and in those with different health conditions.
The study did not find much difference between the EQ-5D-Y and EQ-5D-Y-5L in terms of missing data, reliability and known-group validity. The EQ-5D-Y had problems with knowngroups validity. The EQ-5D-Y-5L demonstrated reliability and validity except discriminant validity with grade. Whereas the EQ-5D-Y-5L performed better than the EQ-5D-Y in terms of discriminant validity, the latter outperformed the EQ-5D-Y-5L in the utilization of response options as well as in terms of empirical validity. The EQ-5D-Y and EQ-5D-Y-5L were found to be reliable for use among children and adolescents in relation to economic evaluation. However, psychometric testing is required for test re-test reliability and responsiveness that could not be carried out in this study due to COVID-19 restrictions. Additionally, the conceptual framework developed demonstrates that HRQoL instruments do not align with local perceptions of health. There are some elements of content validity missing and also concepts that could not translate easily limit the content of these instruments in this setting.
In conclusion, this doctorate research produced Chichewa versions which have potential for use in this setting among children and adolescents but with caveats. This thesis documents the cross-cultural adaptation and validation processes of the EQ-5D-Y, EQ-5D-Y-5L and PedsQL™ 4.0 self-report for use among children and adolescents in Malawi.
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