Prevalence of neck pain and its associated factors in Africa: a systematic review and meta-analysis protocol

Abstract

Introduction

Neck pain is one of the most prevalent musculoskeletal pain conditions with multifactorial impact including pain, disability and reduced quality of life. To the best of our knowledge, no systematic review and meta-analysis is available to provide reliable data on the pooled prevalence of neck pain and its associated factors in Africa. Thus, the objective of this study is to describe a protocol for a systematic review and meta-analysis on the prevalence of neck pain and its associated factors in Africa.

Methods

This systematic review protocol has been designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). A systematic search will be conducted among six key electronic databases including PubMed/MEDLINE, Scopus, African Journals Online, EMBASE, CINAHL and Web of Science, from inception onwards. Population-based cross-sectional studies reporting prevalence of neck pain in the African continent will be included. The primary outcome will be the prevalence of neck pain, whereas the secondary outcomes will be the factors associated with neck pain prevalence. Two independent reviewers will screen the titles/abstracts and relevant full-text articles of potentially relevant studies. Data from eligible studies will be extracted using a customised data extraction form. The risk of bias and methodological quality of the included studies will be assessed using the Newcastle–Ottawa Scale and critical appraisal tool, respectively. A narrative synthesis will be used to summarise the prevalence estimates of neck pain and associated factors. However, if feasible, random-effects meta-analysis will be conducted with Revman V.5.4 software. Additionally, subgroup, sensitivity and publication bias analyses will be conducted.

Discussion

This will be the first systematic review and meta-analysis to systematically identify and synthesise available literature on the prevalence of neck pain and its associated factors in Africa. The results of this review may assist health professionals and policymakers to plan and implement evidence-based strategies that will lessen the burden of neck pain.

Ethics and dissemination

Data from previously published studies will be collected and analysed and hence ethical approval will not be sought for this study. The results of this review will be disseminated through publication in a peer-reviewed academic journal and presentation at relevant academic conferences.

PROSPERO registration number

CRD42021273585.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This protocol defines the first systematic review with meta-analysis to synthesise the prevalence of neck pain and its associated factors in Africa.

• Findings of this review will provide information to health professionals and policymakers in planning and implementing evidence-based strategies for lessening the burden of neck pain in Africa.

• The plan to conduct a meta-analysis, subgroup and sensitivity analyses, as well as inclusion of all age groups, are the strengths of this review.

• Language restriction to studies published in English or French may be a limitation.

Introduction

Musculoskeletal disorders are common and burdensome health problems contributing to disability,^{1 2} with about 1.71 billion people being affected globally.³ Neck pain, being second only to low back pain as the most prevalent musculoskeletal pain condition,⁴ is a complex disorder with a multifactorial impact including pain, disability and reduced quality of life.⁵ Neck pain causes a substantial burden not only to sufferers and their families but also to society due to the costs associated with healthcare, insurance, work absenteeism and loss of productivity.^{5 6}

The occurrence and chronicity of neck pain are believed to be multifaceted,⁷ with individual/personal (eg, age, sex, body mass index and smoking), biomechanical (eg, strenuous physical activity, faulty postures) and psychosocial (eg, stress, anxiety and depression) factors being commonly implicated.^8–10 However, the development and impact of neck pain are likely to vary significantly between and within population groups owing to social, economic, cultural and environmental influence.

According to the most recent Global Burden of Disease estimates, the global prevalence and incidence of neck pain have increased from 124.4 million and 276.5 million cases in 1990 to about 222.7 million and 475.2 million cases in 2019, respectively.¹¹ Neck pain remained one of the leading causes of disability in most parts of the world in 2015.¹ Moreover, among different conditions, it contributes to the highest healthcare expenditure related to musculoskeletal disorders, where about $134.5 billion was reported to have been spent in the USA in the year 2016.¹² This poses a serious problem to the contemporary society.

The burden of neck pain in terms of years lived with disability is higher in women than in men, but increases with age in both genders, peaking at 45–54 years of age, before declining around the age of 70–74 years.¹¹ This is indicative of the significant role of ageing as a contributing factor to the burden of the disease, which unfortunately, is likely to be increasingly overwhelming in the coming decades. In low-income countries, especially those on the African continent, where population growth and ageing are increasing at a very fast pace, this may be an issue to contend with in the future.¹³ Moreover, the current widespread limited healthcare resources, low socioeconomic status, and ineffective or lack of preventive strategies in these countries also make the situation even more dire.¹⁴

In sub-Saharan Africa, the point prevalence of neck pain is high (males 4.1–4.7%; females 6.0–6.8%) and only outranked by the USA (males 5.3%; females 7.6%), Western Europe (males 5.2%; females 7.4%) and East Asia (males 4.8%; females 7.0%).⁵ Unless effective prevention strategies are implemented, the burden of neck pain in Africa is likely to be disturbing in the next few years. Unfortunately, despite the staggering impact of neck pain, it is generally less prioritised and empirically presented,^{5 15} possibly due to the overwhelming incidence of life-threatening conditions such as malaria and HIV/AIDS.¹⁶ However, epidemiological challenges and unavailability of reliable data on the prevalence estimates could possibly explain why disabling musculoskeletal conditions are generally less prioritised in Africa. Thus, to have a better understanding of the impact of neck pain for policymaking, resource allocation and effective translation of research findings into clinical practice in this continent, reliable data on the pooled prevalence of neck pain and its associated factors are warranted.

As is the usual trend globally, low back pain is mostly prioritised over neck pain in research despite the huge global burden of both disorders.^{5 17} In this regard, a systematic review and meta-analysis on the prevalence of low back pain in Africa was conducted in 2017¹⁸ and updated in 2018.¹⁹ This review has opened doors for low back pain-related research and policies. However, a similar review on neck pain in Africa, despite its burden and a plethora of published cross-sectional studies, is lacking.

Following our preliminary search in the International Prospective Register of Systematic Reviews (PROSPERO), MEDLINE, PEDro and the Cochrane Database of Systematic Reviews, it is apparent that no current or underway systematic review and meta-analysis on the prevalence of neck pain and its associated factors in Africa exits. Therefore, the objective of this study is to describe a protocol for a systematic review and meta-analysis on the prevalence of neck pain and its associated factors in Africa.

Specific objectives of this review are:

• To provide accurate and contemporary prevalence estimates of neck pain in Africa according to existing published studies.

• To examine the factors associated with neck pain prevalence in Africa according to existing published studies.

• To critically appraise the methodological quality of the prevalence studies to identify gaps in the literature and highlight areas for improvement in future research.

Methods

Systematic review registration and reporting

This review protocol has been registered with the PROSPERO database on 14 September 2021 (registration number CRD42021273585) and designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement²⁰ (online supplemental appendix 1) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) reporting guideline.²¹ In the event of an amendment to this protocol, a description of the amendment along with the rationale will be updated in PROSPERO.

Data sources and search strategies

Six key electronic databases will be systematically searched from inception to obtain and export relevant articles reporting the prevalence of neck pain in the African continent. The databases are PubMed/MEDLINE, Scopus, African Journals Online, EMBASE, CINAHL and Web of Science. Appropriate search strategies will be used for each of the databases to ensure maximum number of relevant articles. The keywords will be ‘prevalence’, ‘neck pain’, ‘musculoskeletal disorders/pain’ and ‘Africa’. Logically, we anticipate that there will be a lack of the word ‘Africa’ quoted in the title of body of most potentially relevant African prevalence studies. Hence, all individual African countries names will be included in the search strategies. For studies reporting musculoskeletal disorders/pain, neck pain prevalence has to be reported for the study to be included. The full search strategy is presented online supplemental appendix 2.

Eligibility criteria

Studies will be included in the review according to the following criteria: participants, condition or outcome(s) of interest, study design and context. The primary focus of the review is to estimate the prevalence of neck pain in the African continent. Therefore, studies that were conducted in any of the African countries and have reported data on the prevalence of neck pain will be eligible for inclusion. Eligible studies will be population-based cross-sectional studies reporting prevalence data using validated or non-validated questionnaire/scale and conducted in the African continent.

Due to the frequency of studies conducted on musculoskeletal disorders and musculoskeletal pain among African researchers, such studies will be included due to the presence of neck pain in the data of such studies. This will be in addition to studies reporting primarily on neck pain. To be included, studies have to report on prevalence (often proportion) of neck pain in the population of interest. Parameters such as age, gender, language or ethnic group of the participants will not be a barrier for inclusion. However, only studies published in English or French will be eligible since these are the common languages used in scholarly communication in Africa.^{19 22} Studies published in French will be translated by a French-speaking African native and will be validated by cross-checking the French translations with the English abstract of the article, which is often available online, before inclusion. Studies published in other languages other than English and French will be excluded. Lastly, reviews, conference abstracts, commentaries/letter to editors, non-human articles and other grey literature will also be excluded.

Condition or outcome(s) of interest

Primary outcome for the present review will be prevalence proportion of neck pain, defined according to the author’s reported definition. Secondary outcomes will be to identify the factors (eg, individual/personal, biomechanical and psychosocial factors) associated with neck pain prevalence. In the event that neck pain prevalence is not directly reported in proportion and associated 95% CI, estimates from the number of cases and sample size mentioned in each single study will be calculated, if permissible.

Study screening and selection

Relevant articles will first be exported to Zotero software (https://www.zotero.org), where articles will be sorted and duplicates removed before being exported to the Rayyan software (https://rayyan.qcri.org) for screening. The first author (NBM) who is experienced in conducting and publishing systematic reviews as first and coauthor, together with the second author (AAI) who recently completed an intensive course on how to conduct systematic reviews and meta-analyses, will independently screen the articles. In case of unresolved conflict, the third author (JM) will help in resolving the conflict. JM has published a number of systematic reviews as first author. Additional co-authors with experience in conducting systematic reviews will be invited depending on the amount of work load encountered from the databases search. Both title/abstract and full-text screening will be performed using the Rayyan software. A planned PRISMA flow chart showing details of the included and excluded studies at each stage of the study selection process is provided in figure 1.

Figure 1.

Flow chart depicting study selection process.

Data extraction and management

Information to be extracted from the eligible studies will include author name(s), year of publication, country of publication, study design, data collection tool/outcome measure tool(s), population, study setting, sample size, age group/age (range and/or mean±SD), gender, data collection period, neck pain definition, neck pain recall period, reliability/validity of measurement tools, response rates, neck pain prevalence rates (point, period, lifetime) and associated or risk factors of neck pain with their OR. The corresponding authors will be contacted through mail when necessary for any difficulties encountered during data extraction. A prepared customised data extraction form will be used for entering the relevant publication details. The findings of the review will be illustrated through tables and figures.

Risk of bias and methodological quality assessment

The Newcastle–Ottawa Scale (NOS) which consists of three domains (selection, comparability and outcome) will be used in assessing the risk of bias (ROB) in the included studies. A checklist and coding manual language specific to the current review topic will be prepared to aid the two independent raters during ROB assessment. When a primary study meets the methodological expected standard, one star will be awarded for each item in selection and outcome domains, and a maximum of two stars will be awarded for the comparability domain. In the end, studies with star scores from 0 to 4 points will be considered as having high ROB, 5 to 6 points will be considered as having moderate ROB, while 7 to 9 points will be considered as having low ROB.²³

Additionally, the quality of the included studies will also be appraised using a critical appraisal tool as modified by Morris et al¹⁹ (online supplemental appendix 3) where low back pain prevalence in Africa was reviewed and methodological quality of the included studies was appraised using the same tool. We consider this tool to be additionally appropriate for our review due to the similarity of both reviews. Both low back pain and neck pain are types of spinal pain and in both reviews, Africa is the target scope while observational/cross-sectional studies are the designs of interest. In our review, the only modification to the appraisal tool will be to replace low back pain with neck pain. The tool has 10 questions that will be weighed and scored equally. Each question is to be answered by either a ‘yes’ or ‘no’ or ‘unclear’. An option of ‘yes’ will be scored as 1 point, while an option of either ‘no’ or ‘unclear’ connotes 0 point.

Two assessors (most probably NBM and AAI) will independently score the ROB (using NOS) and methodological quality of the included studies. In case of conflicts, a meeting will be organised between the two assessors and where a conflict remains unresolved after the meeting, the last author (JM) will be invited to make the final decision.

Strategy for data synthesis

A descriptive table summarising the key characteristics of each of the included studies will be presented. Meta-analysis will be planned with sufficient clinically and statistically homogeneous and comparable reported outcomes among studies by pooling data using Revman V.5.4 software. The pooled prevalence estimates of neck pain in Africa and associated 95% CI will be calculated. Similarly, for the factors associated with neck pain prevalence, OR and associated 95% CI will be computed. Random-effects model will be used since heterogeneity in the populations of included studies is expected. Statistical heterogeneity will be assessed using I² statistic and its 95% CI, with values of 25, 50, and 75% signifying mild, moderate, and severe heterogeneity, respectively.^{24 25} Pooled prevalence estimates will be graphically depicted using forest plots. In case meta-analysis is not possible due to insufficient homogeneous studies, a narrative synthesis will be performed.

Assessment of publication bias

Potential publication bias will be assessed subjectively using funnel plots, with a symmetrical funnel shape indicating no publication bias while an asymmetrical funnel plot indicating a publication bias.²⁶ Objective assessment of publication bias will be performed using Egger’s linear regression test, with p<0.1 indicating statistically significant publication bias.²⁷

Subgroup and sensitivity analyses

Based on the study and population characteristics, subgroup analyses will be performed for age group (adults and children/adolescents), gender (male and female), study setting (community, industry, hospital, professional and school) and country status (low income, low middle income and upper middle income) as also examined in previous reviews in Africa.^{18 19} For sensitivity analyses, studies with lower methodological quality studies will be excluded to assess if their exclusion would change the results of the analyses.

Patient and public involvement

This study involves a review of publicly available published peer-reviewed papers; hence, patients and the public were not involved.

Ethics and dissemination

Ethical approval will not be sought for this study, as no human subject participants will be involved. Data from previously published studies will be collected and analysed. The results of this review will be disseminated through publication in a peer-reviewed academic journal and presentation at relevant academic conferences.

Discussion

Neck pain remains one of the common health problems affecting the contemporary society. However, despite the significant disability and socioeconomic burden imposed by neck pain, still, less is known about its impact in the African context, perhaps because it is not a life-threatening condition.²⁸ To our best knowledge, this will be the first review to systematically identify and synthesise available literature on the prevalence and associated factors of neck pain in the African continent. Therefore, this will be the first systematic review and meta-analysis to provide a pooled prevalence of neck pain and its associated factors on the African continent, which may assist health professionals and policymakers to plan and implement evidence-based strategies for lessening the burden of neck pain. Furthermore, the review will identify the methodological shortcomings of published African studies on neck pain prevalence for improvement of future research quality.

The plan to conduct a meta-analysis, subgroup and sensitivity analyses are the major strengths of our review. Additionally, the inclusion of all age groups will increase the generalisability of the findings. However, we anticipate limitations to our review due to potential publication bias and heterogeneity among studies, as well as the inclusion of only published studies in English or French.

Ethics statements

Patient consent for publication

Not required.