Research Article: The development and evaluation of content validity of the Zambia Spina Bifida Functional Measure: Preliminary studies

Date Published: July 24, 2017

Publisher: AOSIS

Author(s): Margaret M. Mweshi, Seyi L. Amosun, Mary P. Shilalukey-Ngoma, Esther Munalula-Nkandu, Zuhayr Kafaar.


Very little is known on outcome measures for children with spina bifida (SB) in Zambia. If rehabilitation professionals managing children with SB in Zambia and other parts of sub-Saharan Africa are to instigate measuring outcomes routinely, a tool has to be made available. The main objective of this study was to develop an appropriate and culturally sensitive instrument for evaluating the impact of the interventions on children with SB in Zambia.

A mixed design method was used for the study. Domains were identified retrospectively and confirmation was done through a systematic review study. Items were generated through semi-structured interviews and focus group discussions. Qualitative data were downloaded, translated into English, transcribed verbatim and presented. These were then placed into categories of the main domains of care deductively through the process of manifest content analysis. Descriptive statistics, alpha coefficient and index of content validity were calculated using SPSS.

Self-care, mobility and social function were identified as main domains, while participation and communication were sub-domains. A total of 100 statements were generated and 78 items were selected deductively. An alpha coefficient of 0.98 was computed and experts judged the items.

The new functional measure with an acceptable level of content validity titled Zambia Spina Bifida Functional Measure (ZSBFM) was developed. It was designed to evaluate effectiveness of interventions given to children with SB from the age of 6 months to 5 years. Psychometric properties of reliability and construct validity were tested and are reported in another study.

Partial Text

Spina Bifida (SB) is one of the congenital malformations of the central nervous system that is a major and unrecognised expensive public health problem in much of Africa (Adeleye, Magbagbeola & Olowookere 2010; Blenchowe et al. 2010; Mweshi et al. 2015). It is the commonest of the neural tube defects, and hydrocephalus commonly occurs in association (Fabiano, Doyle & Grand 2010; Qureshi 2010; Sacko et al. 2010). The two are the most recurrent and disabling malformations in neonates in the sub-Saharan African paediatric environment which have a huge impact on the functioning of a growing child (Mweshi et al. 2010).

The study was carried out at the University Teaching Hospital (UTH) and Beit Cure Hospital (BCH). Both the hospitals, which are the only centres providing specialised care to children with SB in Zambia, are found in Lusaka. The two hospitals were comprehensively informed of the nature of the study through letters of permission. The initial process of instrument development involved the identification of the main domains of care in children with SB through a nine-year retrospective study, while confirmation of domains was done through a systematic review of literature. Eventually, parents and caregivers of children with SB and youths with SB were recruited to participate in the process of item generation. Subsequently, expert clinicians managing children with SB validated the items, and ultimately the measure called ZSBFM was constructed. In total, four studies were carried out in the whole process of instrument development.

The results section presents the domains identified and confirmed, items generated from qualitative data, results of the content validation exercise and the item–objective congruence exercise. Subsequently, the process of instrument construction will be presented.

Faced with the clinical problem of lack of evidence on the impact of interventions given to children with SB, the researchers set out to develop a tool expected to fill the gap that existed. The intent was to locally generate a measure with psychometric adequacy that could readily be available, affordable, appropriate and culturally sensitive in assessing the performance of functional skills in children with SB in Zambia. A retrospective study was conducted to identify domains and through a systematic review, the domains were confirmed. Subsequently, items were generated, content validation was performed, and subsequently the first draft was constructed.

A draft measure titled ZSBFM for children with SB in Zambia has been developed. It is meant to help clinicians managing children with SB measure the impact of interventions such as surgery and physiotherapy given to children aged 6 months to 5 years. The measure can provide an opportunity to assess children with SB in performing distinct functional skills based on 77 items categorised into the three main domains of self-care, mobility and social function. The draft ZSBFM has an acceptable level of content validity. Psychometric properties of reliability and validity were measured through Cronbach’s alpha reliability and later I-CVIs and S-CVIs.




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