| Literature DB >> 29532515 |
Lorenzo D Botto1,2, Pierpaolo Mastroiacovo2.
Abstract
Preventing neural tube defects (NTDs) easily qualifies as a high-value opportunity to improve childhood survival and health: the unmet need is significant (major preventable burden), the intervention is transformative (providing sufficient folic acid), and delivery strategies (e.g., fortification) are effective in low-resource countries. Yet, NTD prevention is lagging. Can public health surveillance help fix this problem? Critics contend that surveillance is largely unnecessary, that limited resources are best spent on interventions, and that surveillance is unrealistic in developing countries. The counterargument is twofold: (1) in the absence of surveillance, interventions will provide fewer benefits and cost more and (2) effective surveillance is likely possible nearly everywhere, with appropriate strategies. As a base strategy, we propose "triple surveillance:" integrating surveillance of cause (folate insufficiency), of disease occurrence (NTD prevalence), and of health outcomes (morbidity, mortality, and disability). For better sustainability and usefulness, it is crucial to refocus and streamline surveillance activities (no recreational data collection), weave surveillance into clinical care (integrate in clinical workflow), and, later, work on including additional risk factors and pediatric outcomes (increase benefits at low marginal cost). By doing so, surveillance becomes not a roadblock but a preferential path to prevention and better care.Entities:
Keywords: folic acid; health outcomes; neural tube defects; prevention; spina bifida; surveillance
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Year: 2018 PMID: 29532515 PMCID: PMC5873412 DOI: 10.1111/nyas.13600
Source DB: PubMed Journal: Ann N Y Acad Sci ISSN: 0077-8923 Impact factor: 5.691
Figure 1Left panel: percent NTD reduction with oral folic acid supplementation during the periconceptional period. Figure courtesy of Dr. J. Mulinare; redrawn and modified from Ref. 30. Right panel: NTD rate reduction (and percent reduction) after mandatory flour fortification with folic acid. Reprinted from Ref. 31.
Figure 2Examples of causal chain, from cause to occurrence to outcomes, for selected congenital conditions.
Benefits and potential challenges of integrating the components of triple surveillance
| Surveillance component | Specific benefit | If integrated with other components | Challenge |
|---|---|---|---|
| Blood folate concentration | Measures penetration of intervention in target population: Is sufficient folic acid being effectively delivered to all women of reproductive age? | Helps interpret changes of occurrence rates over time or in specific areas or populations | Sample selection, technical expertise, laboratory capacity, cost, and sustainability (repeated regularly) |
| Neural tube defect occurrence | Direct assessment of key outcome and major determinant of burden of disease | Provides direct link between treatment and health outcomes (morbidity and mortality) | Population coverage, sustainability, inclusion of stillbirths, and elective termination of pregnancy |
| Health outcome assessment | Directly assesses the true burden of disease on individuals, families, and society (morbidity, mortality, disability, and quality of life) | Measures true value of prevention, directly usable to improve care | Robust core data set, longitudinal follow up (the longer the better), and complexity |
Figure 3Modeled relation between red blood cell folate concentration (RBC folate) and risk for neural tube defects (NTD). Data are from Refs. 10 and 11.
Neural tube defect (NTD) surveillance throughout the causal chain, at baseline and after interventions
| Causal chain | Intervention | → Cause (marker) | → Occurrence (prevalence) | → Outcome (life span) |
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| Surveillance focus |
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| Baseline status |
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| After intervention |
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Ideal versus current state of surveillance, with potential strategies for improvement
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| Folate sufficiency | Representative, stratified population surveys with ideal methods (RBC folate), tracked over time |
Rarely done RBC folate testing complex and costly compared with kit‐based folate measurement Often one‐time surveys, not as part of surveillance |
Consider starting with less complex methods (e.g., kit‐based serum survey) for initial tracking (rough estimate) Consider convenience cohorts of women Bundle folate surveys with other nutritional markers for better value and efficiency Incorporate food consumption surveys Expand to other modifiable risk factors of adverse pregnancy outcomes for greater value and efficiency |
| NTD occurrence | Population‐based ascertainment among all pregnancy outcomes (live births, stillbirths, and pregnancy outcomes), with postnatal follow‐up (e.g., at least 1 year of age) |
In many areas, no surveillance and limited health record infrastructure Often only facility based Limited or no capture of home births Often limited to live births Often limited to perinatal period |
Start with facility‐based surveillance and live births (if elective terminations of pregnancy are rare or illegal) Consider area sampling to include home births Focus on core key data, usable also for clinical care (no recreational data collection) Integrate surveillance in clinical workflow rather than a separate system, use data also to improve clinical care Expand to other congenital malformations, especially external malformation (low marginal added cost) |
| Outcomes | Long‐term tracking of multiple outcomes: morbidity, mortality, disability, and quality of life |
In many areas, no data Limited or no civil registration (births and deaths) Limited longitudinal health records and system Unstable populations (migration) |
Integrate clinics and clinicians into system Use outcome data to assess and improve care Use data for awareness and policy development Integrate data or link to general perinatal and pediatric care systems Expand to include other congenital malformations and key pediatric outcomes (low marginal added cost) |
Crosscutting issues:
•Training to build local capacity
•Requires focus and leadership: clear goals, expectations, roles, metrics of success, accountability, and transparency
•Each activity is costly: one must be clear as to “how good is good enough”
Overall framework and operational innovations for improved surveillance
| Proposal | Why | Comment |
|---|---|---|
| A. Overall framework | ||
| Commit for the long term | Good programs take time to work and take root, and surveillance is meaningful if ongoing and sustainable | Commitment also includes training and capacity development and building a surveillance tradition and culture |
| Integrate surveillance into the clinical workflow | Timeliness and quality can quickly degrade if birth defect surveillance is separate and independent of clinical workflow. However, in many areas, this is precisely what happens (and has happened for decades) | Incorporating key elements of birth defects in existing clinical and public programs (including perinatal surveillance programs) decreases data abstraction and should improve speed and accuracy (timely and accurate data) |
| Focus on what matters | Choose data for their usefulness—only if meaningful for reporting and ongoing assessment—avoiding “recreational” data collection | Use the system also for perinatal and pediatric surveillance; information fed back to clinicians is crucial for evaluating and improving care and prevention |
| B. Operational improvements and innovations | ||
| Include all pregnancy outcomes | Include live births, stillbirths, and pregnancy terminations. Stillbirths and terminations are a significant “hidden” toll of birth defects | Stillbirths and terminations of pregnancy are very often undetected, unexamined, and underreported and are often excluded from burden‐of‐disease assessments |
| Expand surveillance to common adverse outcomes | The system should accommodate clinically important outcomes (e.g., low birth weight), which can be relatively simple to track (e.g., birth weight) and share similar risk factors to birth defects | These outcomes are of clinical and public health interest in many safety studies, including of maternal medications and immunizations. Specific tools derived from statistical process control can help monitor several of these additional outcomes |
| Expand surveillance to important exposures and risk factors | Tracking exposures in the underlying birth cohort provides a comparison group (“controls”) for risk factor assessment and functions as an ongoing risk factor surveillance system (e.g., for smoking, diabetes, and immunizations) | Tracking modifiable risk factors is relevant for many birth defects, adverse pregnancy outcomes (e.g., low birth weight), and related pediatric health, thus expanding the usefulness of the system. Examples of such risk factor surveillance include the World Health Organization's STEPS and the CDC's PRAMS |
| Develop a practical and robust sampling frame for large populations | Population‐based surveillance for an entire large LMIC (e.g., India) is extremely challenging, and the data may not be reliable. A sample of small areas rigorously chosen to be representative of the larger region and population(s) can provide reliable, high‐quality data at a fraction of the cost | Sampling of population‐based area surveillance has been used in other contexts (e.g., immunizations and nutrition) to obtain good‐quality information with fewer limitations than convenience‐based facility (hospital) programs, in particular in areas with a large proportion of home births |