Introduction

Cerebral palsy (CP) describes a group of non-progressive motor disorders often accompanied by alterations in sensation, perception, cognition, communication and behaviour.1 2 CP is estimated to be several times more common in disadvantaged parts of the world, low-income and middle-income countries (LMICs), where most children with disabilities reside.3–7 However, due to lack of data from LMICs the exact burden and epidemiology of CP is mostly unknown in majority world population.8

Over the past three decades, the Australian and European CP registers have generated an enormous amount of data on the incidence, prevalence, aetiologies and risk factors of CP in high-income countries (HICs). In addition, they have facilitated intervention trials using the CP registries as sampling frames.9–11 In 2015, the first population-based CP register in an LMIC was piloted in Bangladesh (ie, the Bangladesh CP Register or BCPR).12 In last few years, data from several other CP registers (eg, Indonesia, Vietnam, Nepal, Ghana), population-based cohorts (eg, Uganda) and institution-based surveys (eg, Argentina) in low-resource settings have provided crucial evidence on epidemiology of CP in LMICs.6 13–15 However, a common platform to generate and share comparable data on CP in LMICs was lacking. In 2018, a global network of CP Registers in LMICs was conceived and the Global LMIC CP Register (GLM CPR) was established to improve knowledge base in LMICs and global understanding of CP.16

From our earlier work in Latin America, we have observed that in rehabilitation centres and therapeutic educational centres in Argentina there is a high prevalence of cases of children with disabilities with severe motor compromise.15 17 Furthermore, more than half of them had moderate and severe malnutrition, and that as motor severity increases, the risk of malnutrition, dysphagia, gastro-oesophageal reflux and constipation increases.15 17 We have also observed that children with CP tend to have greater difficulties in growth, and that15 17 these issues are more prevalent in Argentina compared with HICs.18–21 Our previous studies have shown inequalities in access to therapies and nutritional status in children with CP in Argentina, according to their socioeconomic level and motor compromise.15 These differences in socioeconomic status as well as access to healthcare services are likely to have an impact on the risk factors of CP in different population groups and countries in the region. This essential information is missing from the Latin American countries.

Surveillance and register allow systematic data collection on specific variables of interest within a defined population. Similar to any other surveillance/register, the CP registers affiliated with the GLM CPR aims to collect information about CP on agreed core variables following a standard protocol, so that the data generated from CP registers can be compared between LMICs and regions.4 6 13 16 22 For instance, the preliminary data from four LMICs affiliated with the GLM CPR clearly indicate that CP in low-resource settings is often caused by preventable causes such as birth-related neonatal respiratory depression, neonatal encephalopathy and infections.16 Furthermore, in LMICs, the age of CP diagnosis is substantially delayed and the majority of children with CP have severe functional motor limitations. Access to services and, in particular, early intervention is limited in most settings.15 22

In Latin America, findings from a few available studies show that rehabilitation centres are attended mostly by children with CP with severe motor compromise, malnutrition and that the amount of rehabilitation therapies children receive will depend on their socioeconomic level, access to social security and age.23 24 However, there is still a substantial gap in data to understand the epidemiology and the causal pathways to CP in the region. Such data could guide evidence-based approaches to inform local policy for better health and well-being of children with CP in the region and to identify opportunities for prevention. The creation of a unified CP register for Latin America will assist in identification of risk factors for CP and provide opportunities to develop relevant, culturally sensitive and cost-effective prevention strategies and interventions for children with CP in the region.

In this paper, we describe a protocol to develop, implement and evaluate a regional network of CP registers and online data repository of CP in Latin American countries. The network will be affiliated with the GLM CPR. The participating CP registers will follow a standard protocol adapted from the GLM CPR, piloted in Argentina through establishment of the Argentine Register of Cerebral Palsy (RAR-PC) and integrated as a Spanish platform for a Latin American Register. Subsequent plan for expansions is already in place for Mexico, Colombia and other Latin American countries. Together with the GLM CPR, this proposed network of the CP registers will facilitate clinical surveillance and promote research to improve the care of people with CP in the region. In addition, this initiative will allow cross-cultural comparisons of data from different LMICs.

Aims and objectives

This study aims to establish a Latin American multicountry network and online data repository of CP called Latin American Cerebral Palsy Register (LATAM-CPR). The LATAM-CPR will be a resource for research to better understand the epidemiology of CP in Latin American countries; provide information for regional strategies and models for prevention, early diagnosis and intervention; and will support the global network for CP in LMICs through research, capacity building and service delivery.

Our specific objectives are to:

Establish the technical infrastructure for the LATAM-CPR to bring together data on agreed core variables from different Latin American countries following a harmonised protocol adapted from the GLM CPR.

Provide initial support to collaborating organisations/countries to establish their own CP register in partnership with LATAM-CPR.

Use the LATAM-CPR database as a resource for research.

Inform on epidemiology of CP (prevalence, risk factors, motor function and clinical features/severity, associated impairments) among children in Latin American countries.

Develop relevant, culturally sensitive and cost-effective prevention strategies.

Use this LATAM-CPR database and collaborator network as a platform to study other health related issues (such as nutrition, education, rehabilitation, health-related quality of life, survival probability) among children with CP in Latin American countries.

Build LATAM-CPR network capacity for project implementation, research, service delivery and advocacy through ongoing and future collaborations.

Hypothesis

We hypothesise that the burden and causal pathways of CP in low-resource settings of the Latin American Countries differ from those in HICs, and that these differences are linked to the socioeconomic level of families and access to healthcare and may vary between and within countries.

The LATAM-CPR will be affiliated with the GLM CPR network and will contribute to the knowledge base for future comprehensive studies in different regions of the world. In this way, it will facilitate the development of regionally applicable models for the early diagnosis and early intervention for children with CP in Latin American countries as well as other countries with similar context.

Methods and analysisEstablishment of the LATAM-CPR

The LATAM-CPR will be a multicountry network of CP registers in Latin American countries. The LATAM-CPR project will support establishment of new CP registers and capacity development of emerging CP registers in the Latin American region following a harmonised protocol adapted from the GLM CPR.

Geographical location of the LATAM-CPR

Latin America (LATAM) is a proportion of the American Continent, defined as the region of the Americas where Latin languages are spoken (Spanish, Portuguese and French). From Mexico to Argentina, this region consists of 20 countries and 14 dependent territories including the Caribbean. LATAM has an approximate area of 19 million km2, with more than 650 million population.25 Brazil, Mexico, Colombia, Argentina and Peru are more population-dense countries in the region (figure 1).

Figure 1

Latin American Region colour coded accorded to population density. Adapted from World Bank Data Team.25

Implementation of the LATAM-CPR

The members of the Argentinean CP Register team are currently leading this network and have ongoing collaboration for training and research projects with other Latin American countries. The Institute of Clinical and Epidemiological Research (INICyE) of the National University of Cordoba in Argentina will act as the coordinating institution for the LATAM-CPR. The team based at INICyE will also train and supervise the countries in the adaptation of forms to their local context, assessments and data collection. We plan to start with Spanish-speaking countries in the first stage and then expand the network activities to other countries whose language is Portuguese, such as Brazil. As a coordinating and implementing partner of the LATAM-CPR, the team at INICyE has also successfully piloted the protocol and started registration of children with CP into the Argentinian Cerebral Palsy Register (RAR-PC) since October 2021. Agreements have been established with Mexico and Colombia. In Mexico, the Mexican Academy for Cerebral Palsy and in Colombia with the Rehabilitation Committee of Antoquia will lead this work. In addition, agreements will be established with the organisation Teleton Mexico and Teleton Argentina, being able to subsequently include all Teleton centres of the Oritel Network present in more than 13 countries of LATAM.

Study participants and case definition

Children with confirmed CP aged less than 18 years will be registered into the country-specific CP registers of the LATAM-CPR. The LATAM-CPR will use the definition of CP accepted by other CP register networks which allows the use of any CP definition that includes the following five key elements common to published definitions.1 26

Cerebral palsy:

This is an umbrella term for a group of disorders.

It is a condition that is permanent but unchanging.

It involves a disorder of movement and/or posture and motor function.

It is due to a non-progressive interference, injury or abnormality.

The interference, injury or abnormality originates in the immature brain.

Diagnostic algorithm

This project will use the diagnostic algorithm for early diagnosis of CP or high risk of CP that was developed as an international clinical practice guideline.1 26 It will provide an opportunity to implement best practices among clinicians and researchers involved in the project both at the community level and in hospitals/institutes. We are currently testing and adapting the most up-to-date CP diagnostic algorithm to local settings.27

Inclusion criteria

All individuals with CP who meet any of the five-dimensional elements mentioned in the ‘case definition’ will be included in the CP registers. For children under 5 years of age, their inclusion in the CP register will be rereviewed when the individual reaches 5 years of age. If new information becomes available, a case entry may be updated, which may involve inclusion or exclusion of that child from the CP register.

Recruitment of children with CP into the country-specific CP registers

The LATAM-CPR will adopt both institution based, in rehabilitation and health centres, and community/ population-based surveillance mechanisms in three three-stage steps to establish CP registers in the countries and dependent territories affiliated with the network (figure 2).

Figure 2

Stages of recruitment in LATAM-CPR. Grey area correspond to Institution-based recruitment, and white area to community-based/ population-based recruitment. LATAM-CPR, Latin American Cerebral Palsy Register.

Institution-based recruitment

A pragmatic approach will be undertaken to identify potential sites/facilities for identification and recruitment of children with CP in the respective CP registers. In the first stage, children with CP will be recruited from rehabilitation centres where they have access to rehabilitation therapies. In a second stage of the institution-based recruitment, data will be collected from hospitals, health institutions and non-governmental organisations where children with CP could be attending for health issues (non-rehabilitation), social or economic assistance. Once identified, the facilities (ie, prospective surveillance/study sites for CP register) will be invited to participate in the respective country-specific CP registers. A memorandum of understanding will be signed with those institutions who show interest to join the platform (ie, CP register and the LATAM-CPR through a deidentifiable data sharing agreement). All children with CP who meet the inclusion/exclusion criteria will be invited into the CP register following a harmonised protocol. Additionally, if available, institutional records will be checked to retrace children with CP who attended those facilities previously, however, are no longer taking services from there to invite them to participate in the register.

Although this surveillance mechanism will not produce population-level data, it is cost-effective and is equally important as these research sites are primarily rehabilitation healthcare facilities, which will allow implementation of best practices through training of physicians and other healthcare professionals at these sites.

Community-based/population-based recruitment

In Latin American countries, a large part of the population is covered by healthcare services provided by public and private institutions and NGOs, thus institution-based surveillance including all rehabilitation units in a particular site of country-specific CP registers is likely to capture most of the children with CP in the area. However, there may be areas which are far from rehabilitation units mostly localised in the large cities, and financially disadvantaged families who may lack access to these institutions. To maximise the registration and coverage of the CP register, we subsequently plan to employ a community-based recruitment strategy to the remote and distant locations of the project area. We will adapt the key informant method (KIM) to identify and register children with CP from the community-based settings. KIM is a validated and widely practised method to ascertain children with suspected disability from local communities especially in low-resource settings.16 28 KIM involves identification and training of local volunteers known as KI, the KIs receive structured training on identification of children with suspected disability (eg, CP) and who then undergoes detailed neurodevelopmental assessments for confirmed diagnosis. The detail methods of using KIM in CP research is available in other publications.4 13

As mentioned earlier, the application of KIM will be conducted in those areas where people in the community have less access to rehabilitation institutions. The number of the KIs will vary depending on the geographical area and population density. In previous studies in Bangladesh, one KI for approximately 400 households was trained to identify children with disability in a defined geographical area. The number of KIM trainings will be estimated and conducted following a standard protocol previously used in other LMICs.29 30 The need for implementation and number of KIs will be determined by each coordinating institution in each country.

Additionally, information about the country-specific CP registers will be disseminated through social networks of participating institutions, through a web page of the register and the GLM CPR website, in order to contact families who wish to join on a voluntary basis. Their data will be collected and will be contacted for interviews.

Clinical assessment and data collection

Children with confirmed CP will undergo detailed clinical assessment by a multidisciplinary team (composed of medical officer, physiotherapist, occupational therapist, nutritionist and psychologist as available) following a harmonised protocol prior registration into the country-specific CP registers of the LATAM-CPR. In addition, available medical records will be reviewed, and a detailed clinical history will be collected from the primary caregivers and by interviewing the primary physicians of children with CP for confirmed diagnosis and registration into the registers. The lead implementing partner/organisation for each country-specific CP register will receive training on the harmonised protocol, diagnostic algorithm and registration by the LATAM-CPR and GLM CPR team for consistent data collection and documentation.

The lead implementing partner will thereafter train the clinical assessment team (composed of at least a medical officer and a physiotherapist/occupational therapist) of all participating institution/organisation in that country. Training sessions will be conducted virtually with practical cases for both the clinical assessment team and the health professionals from the collaborating institutions. The lead implementing partner will also oversee and supervise the clinical assessment team in data collection, discuss complex cases and registration of children with CP in the country-specific CP register.

Data collection on agreed core variables

Information on agreed core variables will be collected for each child with CP registered into the respective CP registers following a harmonised protocol. Clinical assessment team members will collect data by interviewing the primary caregiver of children, real-time assessments and review of clinical histories using a structured data collection/registry form adapted from the GLM CPR and ACPR (see the registration form section). Core variables will include: (1) sociodemographic and socioeconomic characteristics, (2) birth related history (eg, prenatal, perinatal and postnatal history), (3) predominant type and topography, (4) timing of onset of the brain injury, age of diagnosis and cause of CP, (5) motor function and associated impairments, (6) educational and rehabilitation status and (7) nutritional status and feeding difficulties.

Registration form

Each CP register included in the LATAM-CPR will use a standard registration form adapted from the GLM CPR and the ACPR to collect data on agreed core variables as discussed in the earlier section. The sociodemographic and socioeconomic part of the registration form will be aligned to the national-level survey questionnaires in each participating country. Predominant motor type and topography will be documented using the ACPR classification.11 Gross motor function will be classified using Gross Motor Function Classification System (GMFCS) level.31

The registration form will be translated into local language to collect information on agreed core variables as discussed above and will be adapted to the local context of each country. The cross-cultural adaptation of each form involves a process of adapting the words to the specific type of Spanish language of the country, making adaptations that facilitate the comprehension of the instrument by local families and professionals. For this process, the adapted instrument will be reviewed by a panel of experts composed of 5–10 people, including health professionals and caregivers of persons with CP and/or persons with CP. Suggested changes will be made and resubmitted to the expert panel until more than 90% of its members agree. Following the Delphi method, as many rounds as necessary will be made.32

A Spanish version of the register form has already been developed and is in use for Argentina CP Register. Since Spanish is the most widely spoken language in Latin America, the Argentine CP register form will be adapted to those Spanish-speaking countries. However, in the case that the language of a country is not Spanish or the translation into another language is required, the instrument will be translated following internationally recognised methodological guidelines (eg, forward-backward translation method).33 34 Individual CP registers may also choose to collect additional information considering their local context and resource availability.

The form will be available both in electronic and paper-based format, as there are many locations where access to electronic devices and the internet may not be available for data collection. Data collected using paper-based format will be digitalised and then entered to the electronic format by a data entry operator. Each register in each country will be responsible for coordinating these tasks.

Data sharing and collation

As mentioned above, the LATAM-CPR will have a coordinating office in Argentina at INICyE where the country’s CP register has already been initiated. Each participating CP register will have a designated data custodian for their respective register (eg, the principal investigator for that site). After data collection, deidentified coded data from each CP register will be deposited on a regular basis to an online data repository. The project investigators and selected project personnel from each CP register affiliated with the LATAM-CPR will have access to the online data repository. The data quality and completeness will be checked on a regular basis by a dedicated data management officer located at the coordinating office in Argentina. The line-listed deidentified data from the LATAM-CPR will be later shared with the GLM CPR network to generate consistent data on epidemiology of CP among children in LMICs. Deidentified data can also be requested by other researchers, academicians, healthcare professionals following standard data request and ethics application and approval by respective CP register office.

The digital repository Lime Survey, provided by the National University of Cordoba, the coordinating institution, will be used for the surveys. The Lime Survey system generates a survey stored separately for each user; in this case each country will have a survey managed from Argentina. The connection from each browser to the servers is SSL encrypted. This data is at rest and encrypted, stored securely on a different drive.

To avoid duplicate registrations, an identification code will be created for each child in each country. The code will contain the date of birth, last four digits of their national identification number and gender. We also plan to develop an app/site where a person (such as a healthcare worker) can enter necessary information and check if a child with CP is registered to the respective country-specific CP register. If they are not, there will be stepwise instructions for a person to contact a nearby institution to arrange subsequent assessments for confirmed diagnosis and registration into the CP register.

Data analysis, reporting and publications

Descriptive analysis of the epidemiological data for individual country CP registers will be conducted separately. Categorical variables will be described in absolute and relative values with their respective 95% CI. Descriptive epidemiological measures, such as prevalence and incidence of CP will be estimated from the population level data. We will use nationals’ statistics of each county and most recent census data to calculate the denominator population. The regional differences and trends in CP epidemiology including risk factors, clinical and motor function profile, rehabilitation, and nutritional status will be reported. Furthermore, the role of socioeconomic status and potential predictors of poor functional outcome among children with CP in individual countries as well as using combined data will be explored.

Creation of the LATAM-CPR

Different activities are envisaged for the creation of the LATAM-CPR (figure 3). These processes will include:

Establishment of the LATAM-CPR

Designation of an in-country coordinating institution and signing of agreement with LATAM-CPR.

Recruitment of a register staff member in each country to operationalise the register.

Cross-cultural adaptation and digitalisation of the register form for the country.

Obtaining ethical approval from participating services and institutions for data collection.

Creation of a register follow-up committee for each country inviting families, persons with CP and health professionals to participate.

Promote the incorporation of new health and rehabilitation centres into the register and organise data collection procedures using the KIM in the study area to capture families who do not attend health centres.

Dissemination of the register procedures to members of relevant health professions, local CP organisations and to persons with CP, who will be invited to report ‘CP records’ to the register.

Follow-up reports to be sent by each country to the LATAM-CPR central office. From these reports, partial results will be published with free access to the community.

Procedures for countries to join the LATAM-CPR collaboration.

Invitation to potential collaborators for joining the country-specific CP registers.

Establish a process for sharing of the non-identifiable line listed data with LATAM-CPR.

Establish a process for sharing data from the LATAM-CPR with the GLM CPR.

Figure 3

Creation of the Latin American Cerebral Palsy Register (LATAM-CPR). CP, cerebral palsy; DPOs, disabled persons organisations; EOI, expression of interest; GLM CPR, Global Low-Income and Middle-Income Country Cerebral Palsy Register; MoU, memorandum of understanding.

Register follow-up committees

LATAM-CPR will have a network of follow-up committees. The follow-up committee will consist of families, caregivers, people with disabilities and health professionals who join as volunteers. Each country will have its own register follow-up committee with a chairperson. The chair will be elected by the committee members and will rotate every 2–3 years. With regular meetings, the follow-up committee will take action in decision making. It will be responsible for evaluating the development of the activities, developing new strategies for recruitment and dissemination of results, and managing recreational and inclusive activities for persons with disability and their community and other advocacy activities.

Patient and public involvement

Patients and/or the public were involved in the design or conduct, or reporting, or dissemination plans of this research. See the Methods section for further details.

Discussion

The LATAM-CPR will be the first network of Latin American countries conducting multicountry epidemiological research on CP in the region. The network will adapt the protocol and model of the GLM CPR, thus generating comparable data on epidemiology of CP in the region and other LMICs affiliated with the GLM CPR. The GLM CPR has ongoing collaboration with more than 12 LMIC based CP registers,11 12 16 26 including Argentina since 2020. Preliminary data from the GLM-CPR showed that in LMICs from South Asia and Africa, most of the children had acquired the CP prenatally and perinatally, with a comparatively delayed diagnosis (median age of diagnosis is 3 years). Data also suggest that most children with CP in LMICs present moderate to severe motor compromise with a GMFCS levels III–IV and malnutrition, without access to adequate rehabilitation services. The GLM CPR data also enabled countries to compare the predictors of not receiving rehabilitation and malnutrition among children with CP in LMICs.16 22 35 It would be interesting to know whether these epidemiological data are similar in Latin American region.

The protocol and registrations forms for LATAM-CPR were adapted from the GLM CPR in consultation with international experts on global CP programme, content specialists and epidemiologists. The data to be generated from the LATAM-CPR will be comparable and will be used to provide initial estimates of CP prevalence, local aetiological risk factors, access to health and rehabilitation of persons with CP and to identify the rehabilitation and participation needs of people with CP in each country and the region in the region. Furthermore, the data will be comparable to other LMIC based CP registers affiliated with the GLM CPR thus will contribute substantial evidence to understand of the epidemiology of CP and develop need-based early diagnosis and intervention programme for children with CP in LMICs where the majority of children with disability resides.

Another strength is that the registration form to be used in the LATAM-CPR has already been translated into the Spanish language and piloted as part of the Argentina CP Register. Argentina has received funding from the Cerebral Palsy Alliance Research Foundation to finance its registry activities starting in June 2022 for 2 years, which will help to provide an advisory structure for other countries that join LATAM-CPR. Collection of data in line with other established registers, epidemiological information from LATAM region will be able to be compared and analyse the findings considering other HICs and LMICs. One major potential challenges or limitations of the LATAM-CPR is consistent funding support to establish a working structure in each participating country and sustain the activities of the participating CP registers. To overcome this challenge, we will first work in collaboration with institutions that can allocate human resources for the registry’s activities and will seek funding for doctoral scholarships in the different countries. We will also seek international funding to support our work. Another limitation in project administration is the geographical distance between countries. To overcome this, regular virtual meetings and training sessions will be organised for networking and monitoring of the works among the participating countries. We expect that establishment of a Latin American CP register will, therefore, address the research gap among one of the most vulnerable groups in this region, that is, children with CP and their families, and will inform local, national and regional policy. A possible limitation may be the recruitment of cases with less motor involvement (children with CP with GMFCS levels I and II). Although different data collection strategies will be applied, such as institution-based and KIM, we must recognise that there may be a bias in recruitment.