Poverty and Risk of Cleft Lip and Palate: An Analysis of United States Birth Data

Characterizing Interventions and Family Assistance of a Nurse Navigation Program in Orofacial Cleft Care

OBJECTIVE

Characterize the interventions and assistance employed by a cleft nurse navigator (CNN) which have mediated improvement in care equity at our institution.

DESIGN

Retrospective study.

SETTING

Academic tertiary care center.

PATIENTS, PARTICIPANTS

Patients presenting with cleft lip and/or cleft palate presenting between August 2020 and August 2021 with exclusions for syndromic diagnosis, Pierre-Robin sequence, late (> 6 months) presentation, and prior cleft surgery at outside institutions.

INTERVENTIONS

Multidisciplinary cleft nurse navigator program.

MAIN OUTCOME MEASURE(S)

Family interactions with the CNN by phone, text, and email across the first year of life including feeding support, nasoalveolar molding (NAM) assistance, appointment scheduling, financial assistance, addressing perioperative concerns, and facilitating physician consults. Patient weight and surgical timing were also recorded.

RESULTS

Sixty-nine patients were included with a total of 639 interactions between the CNN and families. Scheduling support (30%), addressing perioperative concerns (22%), and feeding support (20%) were the most common interactions. Feeding support and NAM assistance were heavily distributed in the first 3 months of life compared to after 3 months (P < .001). Median age at first contact was 1 week (range: 22 weeks gestation-14 weeks). There was no difference in the proportion of families receiving feeding support, NAM assistance, or scheduling assistance based on insurance status or race (P > .05 for all).

CONCLUSIONS

Scheduling assistance, addressing perioperative concerns, and feeding support are the predominant methods by which the CNN interacts with and assists families of patients with cleft conditions. CNN service distribution is largely equitable between demographic groups.

A Geospatial Analysis of Barriers to Cleft Lip and Palate Care in the United States

OBJECTIVE

This study evaluates the geospatial distribution of cleft lip and/or cleft palate (CL/P) care in the United States, assesses disparities between families with and without one-hour proximity to CL/P care, and recommends interventions for improving access.

DESIGN

We identified American Cleft Palate Craniofacial Association-approved CL/P teams and calculated a one-hour driving radius around each clinic. We then used census data to compare risk factors for developing cleft (i.e., incidence risk factors) and obstacles to care (i.e., access risk factors) between counties with and without one-hour proximity.

RESULTS

We identified 187 CL/P teams in 45 states. Most were in the South (n = 60, 32.0%), though children in the Middle Atlantic had the greatest access to care. Alabama, Mississippi, Tennessee, and Kentucky had the least access. Children without access were 39% more likely to have gestational tobacco exposure, 8% more likely to have gestational obesity exposure, and 28% less likely to have health insurance (p < 0.01). Children without access in the South were 29% more likely to have a low birth weight and 46% more likely to be living below the poverty line (p < 0.01). Children with access were twice as likely to live in immigrant families and 7-times more likely to speak English as a second language.

CONCLUSIONS

Pronounced disparities affect patients with and without one-hour access to CL/P care. Interventions should address care costs for patients living furthest without access and language barriers for patients with access that speak English as a second language.

Epidemiologic Trends of Cleft Lip and Palate in a Southern State: A 30-Year Follow-Up

OBJECTIVES

Children's of Mississippi at the University of Mississippi Medical Center serves as the state's only American Cleft Palate-Craniofacial Association-approved cleft team at the only pediatric hospital in the state. The goal of this study is to report geographic and demographic patterns of patients with orofacial cleft (OFC) treated at Children's of Mississippi, which are lacking.

METHODS

Patients with OFC treated at Children's of Mississippi from 2015 to 2020 were included. Demographic data were collected, including birth county and total live births from state data. Significant differences between incidence of OFC among public health regions of Mississippi were examined using analysis of variance (P < 0.05). Cases were compared with historical data from 1980 to 1989.

RESULTS

There were 184 patients who presented with OFC, with a statewide incidence of 0.83 per 1000 live births among 222,819 live births in the state across 6 years. The incidence of OFC was 0.83/1000 for Whites and 0.82/1000 for non-Whites versus a historical rate of 1.36 and 0.54, respectively. Significantly fewer children in the northern region (0.25/1000) were born with OFC than in central (1.21; P < 0.001) and southern (0.86; P < 0.001) regions.

CONCLUSIONS

Results from this study suggest changing regional patterns of OFC in Mississippi. Although rates increased among non-White infants, the overall incidence of OFC has decreased compared with historical data. The findings may reflect actual incidence patterns in the state or the proximity of certain regions to Children's of Mississippi. Further study may reveal regional differences in risk factors underlying OFC incidence, and/or issues with access to cleft care for different regions in the state.

Impact of Prenatal Care on Newborn Complications for Infants with Cleft Lip with or Without Cleft Palate

OBJECTIVE

To determine the association between prenatal care and cleft lip with or without cleft palate (CL ± P) and examine differences in newborn complications among infants diagnosed with CL ± P as a function of prenatal care.

DESIGN

Population-based retrospective cohort study.

SETTING

2018 United States National Vital Statistics System-Natality component (NVSS-N) was used to examine nationwide birth certificate data.

PARTICIPANTS

3,414,338 infants from the 2018 National Vital Statistics System, of which 1,699 had CL ± P.

MAIN OUTCOME MEASURE

Diagnosis of CL ± P and presence of newborn complications as a function of prenatal care.

RESULTS

Significant differences were found among various infant- and mother-specific variables when baseline comparisons were made between infants with and without CL ± P. After controlling for baseline differences, results indicated decreased odds of a diagnosis of CL ± P in cases where overall adequate prenatal care was obtained (OR = .841; 95% CI .757, .934), including prenatal care beginning in the 1st trimester (OR = .839; 95% CI .750, .939) and an adequate number of prenatal visits received (OR = .864; 95% CI .764, .976). Of infants with CL ± P, reduced odds of the infant admitted to the neonatal intensive care unit (OR = .777; 95% CI .613, .985) or transferred (OR = .601; 95% CI .407, .888) were apparent when adequate prenatal care was received.

CONCLUSION

Results suggest adequate prenatal care not only reduces the likelihood of CL ± P in infants but may also decrease the severity of negative outcomes in infants diagnosed with CL ± P. These findings emphasize necessity for adequate prenatal care.

Maternal factors in the origin of cleft lip/cleft palate: A population-based case-control study

OBJECTIVES

Orofacial clefts are among the most common birth defects, with an estimated worldwide incidence of around 1.5-1.7 per 1000 live-born babies. The most frequent form of orofacial clefts is cleft lip with or without cleft palate (CL ± CP). The role of environmental factors in the development of clefts is unclear in most patients, thus the aim of this study was to estimate possible maternal risk factors in the origin of CL ± CP.

MATERIALS AND METHODS

1648 CL ± CP cases, 2654 matched controls and 57 231 population controls were evaluated from The Hungarian Case-Control Surveillance of Congenital Abnormalities. Maternal factors during the critical period in cases and controls were compared. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were estimated in a multivariable conditional logistic regression model.

RESULTS

Among socio-demographic data, we have found significant differences between maternal employment. The proportion of unskilled mothers (6.5%) were higher in the CL ± CP group than in controls (3.5%). Medically recorded maternal anaemia, excessive vomiting and threatened abortion were associated with a higher risk of CL ± CP. An elevated risk was also found in various acute illnesses such as influenza (OR: 2.4, 95% CI: 3.0-5.8), acute bronchitis (OR: 4.5, 95% CI: 1.6-12.6) and urinary tract infections (OR: 3.5, 95% CI: 2.0-6.0). Maternal migraine and essential hypertension occurred more frequently in the mothers of cases than in controls.

CONCLUSION

The findings of this study suggest that maternal diseases and lifestyle factors during the first trimester play a significant role in the development of CL ± CP.

Incomes to Outcomes: A Global Assessment of Disparities in Cleft and Craniofacial Treatment

OBJECTIVE

Recent investigations focused on health equity have enumerated widespread disparities in cleft and craniofacial care. This review introduces a structured framework to aggregate findings and direct future research.

DESIGN

Systematic review was performed to identify studies assessing health disparities based on race/ethnicity, payor type, income, geography, and education in cleft and craniofacial surgery in high-income countries (HICs) and low/middle-income countries (LMICs). Case reports and systematic reviews were excluded. Meta-analysis was conducted using fixed-effect models for disparities described in three or more studies.

SETTING

N/A.

PATIENTS

Patients with cleft lip/palate, craniosynostosis, craniofacial syndromes, and craniofacial trauma.

INTERVENTIONS

N/A.

RESULTS

One hundred forty-seven articles were included (80% cleft, 20% craniofacial; 48% HIC-based). Studies in HICs predominantly described disparities (77%,) and in LMICs focused on reducing disparities (42%). Level II-IV evidence replicated delays in cleft repair, alveolar bone grafting, and cranial vault remodeling for non-White and publicly insured patients in HICs (Grades A-B). Grade B-D evidence from LMICs suggested efficacy of community-based speech therapy and remote patient navigation programs. Meta-analysis demonstrated that Black patients underwent craniosynostosis surgery 2.8 months later than White patients (P < .001) and were less likely to undergo minimally-invasive surgery (OR 0.36, P = .002).

CONCLUSIONS

Delays in cleft and craniofacial surgical treatment are consistently identified with high-level evidence among non-White and publicly-insured families in HICs. Multiple tactics to facilitate patient access and adapt multi-disciplinary case in austere settings are reported from LMICs. Future efforts including those sharing tactics among HICs and LMICs hold promise to help mitigate barriers to care.

Evidence-Based Practices in Cleft Palate Surgery

LEARNING OBJECTIVES

After studying this article, the participant should be able to: (1) Understand the embryologic origins, cause, and incidence of cleft palate. (2) Review the anatomy and common classifications of cleft palate and associated defects. (3) Describe surgical techniques for palatoplasty and understand their respective indications. (4) Gain an awareness of general perioperative care considerations, timing of repair, and risk factors for and operative mitigation of complications.

SUMMARY

Cleft palate affects 0.1 to 1.1 per 1000 births, with a higher incidence in certain ethnic groups but affecting both sexes equally. Cleft palate may occur in isolation or in combination with cleft lip or in association with other congenital anomalies including various syndromes. The goals of cleft palate repair are to anatomically separate the oral and nasal cavities for normal feeding and improved speech and minimize the risk of oronasal fistulas, velopharyngeal dysfunction, and disruption of facial growth. This review discusses the incidence, causes, and classification of cleft palate; surgical techniques for palatoplasty and perioperative patient management; and complications of palatoplasty.

Impact of Neighborhood Deprivation and Social Vulnerability on Outcomes and Interventions in Patients with Cleft Palate

OBJECTIVE

To examine whether neighborhood disadvantage impacts length of follow-up, interventions, and outcomes for patients with cleft palate.

DESIGN

Retrospective cohort.

SETTING

Cleft Palate Craniofacial Institute Database at St. Louis Children's Hospital.

PATIENTS/PARTICIPANTS

Patients with cleft palate following in St. Louis Children's Hospital Cleft Palate Multidisciplinary Team Clinic.

INTERVENTIONS

Primary palatoplasty between 2012-2017. Patients were divided into quartiles across area deprivation index (ADI) and social vulnerability index (SVI), two validated, composite metrics of neighborhood disadvantage, to examine whether living in neighborhoods from different deprivation quartiles impacts outcomes of interest.

MAIN OUTCOME MEASURE

Follow-up through age 5, surgeries and surgical complications, speech, developmental, and behavioral outcomes.

RESULTS

205 patients were included. 39% of patients belonged to the most deprived ADI quartile, while 15% belonged to the most vulnerable SVI quartile. There were no differences between ADI or SVI quartiles in number of operations received (p ≥ 0.40). Patients in the most deprived ADI quartile were significantly more likely to have speech/language concerns (OR 2.32, 95% CI [1.20-4.89], p = 0.01). Being in a more vulnerable SVI quartile was associated with developmental delay (OR 2.29, 95% CI [1.04-5.15], p = 0.04). ADI and SVI quartile did not impact risk of loss to follow-up in the isolated and combined cleft lip and palate subgroups (p ≥ 0.21).

CONCLUSIONS

Neighborhood disadvantage impacts speech and developmental outcomes in patients with cleft palate despite comparable length of follow-up in multidisciplinary team clinic.

US air pollution is associated with increased incidence of non-syndromic cleft lip/palate

Maternal cigarette use is associated with the fetal development of orofacial clefts. Air pollution should be investigated for similar causation. We hypothesize that the incidence of non-syndromic cleft lip with or without palate (NSCLP) and non-syndromic cleft palate (NSCP) would be positively correlated with air pollution concentration.

METHODS

The incidence of NSCLP and NSCP per 1000 live births from 2016 to 2020 was extracted from the Centers for Disease Control and Prevention Vital Statistics Database and merged with national reports on air pollution using the Environmental Protection Agency Air Quality Systems annual data. The most commonly reported pollutants were analyzed including benzene, sulfur dioxide (SO2), particulate matter (PM) 2.5, PM 10, ozone (O3), and carbon monoxide (CO). Multivariable negative binomial and Poisson log-linear regression models evaluated the incidence of NSCLP and NSCP as a function of the pollutants, adjusting for race. All p-values are reported with Bonferroni correction.

RESULTS

The median NSCLP incidence was 0.22/1000 births, and isolated NSCP incidence was 0.18/1000 births. For NSCLP, SO2 had a coefficient estimate (CE) of 0.60 (95% CI [0.23, 0.98], p < 0.007) and PM 2.5 had a CE of 0.20 (95% CI [0.10, 0.31], p < 0.005). Among isolated NSCP, no pollutants were found to be significantly associated.

CONCLUSION

SO2 and PM 2.5 were significantly correlated with increased incidence of NSCLP. The American people and perinatal practitioners should be aware of the connection to allow for risk reduction and in utero screening.

Association between gestational exposure and risk of orofacial clefts: a systematic review and meta-analysis

BACKGROUND

The occurrence of orofacial Clefts (OFCs) is a congenital disease caused by many factors. According to recent studies, air pollution has a strong correlation with the occurrence of OFCs. However, there are still some controversies about the current research results, and there is no relevant research to review the latest results in recent years.

OBJECTIVE

In this paper, the authors conducted a systematic review and meta-analysis to explore the correlation between ambient air pollution and the occurrence of neonatal OFCs deformity.

METHODS

We searched Pubmed, Web of science, and Embase databases from the establishment of the database to May 2023. We included observational studies on the relationship between prenatal exposure to fine particulate matter 2.5 (PM2.5), fine particulate matter 10 (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO) and the risk of cleft lip (CL), cleft palate (CP), cleft lip with or without palate (CL/P). the Newcastle-Ottawa quality assessment scale (NOS) was used to evaluate the quality of the literature. Funnel plot and Egger's regression were used to verify the publication bias. Random effect model or fixed effect model was used to estimate the combined relative risk (RR) and 95% confidence interval (95%CI).

RESULTS

A total of eleven studies were included in this study, including four cohort studies and seven case-control studies, including 22,453 cases of OFCs. Ten studies had low risk of bias and only one study had high risk of bias. Three studies reported that PM2.5 was positively correlated with CL and CP, with a combined RR and 95%CI of 1.287(1.174,1.411) and 1.267 (1.105,1.454). Two studies reported a positive correlation between O3 and CL, with a combined RR and 95%CI of 1.132(1.047,1.225). Two studies reported a positive correlation between PM10 and CL, with a combined RR and 95%CI of 1.108 (1.017,1.206). No association was found between SO2, CO, NO2 exposure during pregnancy and the risk of OFCs.

CONCLUSION

The results of this study showed that there was a significant statistical correlation between exposure to PM10, PM2.5, O3 and the risk of OFCs in the second month of pregnancy. Exposure assessment, research methods and mechanisms need to be further explored.

Hybrid Bionic Nerve Interface for Application in Bionic Limbs

Intuitive and perceptual neuroprosthetic systems require a high degree of neural control and a variety of sensory feedback, but reliable neural interfaces for long-term use that maintain their functionality are limited. Here, a novel hybrid bionic interface is presented, fabricated by integrating a biological interface (regenerative peripheral nerve interface (RPNI)) and a peripheral neural interface to enhance the neural interface performance between a nerve and bionic limbs. This interface utilizes a shape memory polymer buckle that can be easily implanted on a severed nerve and make contact with both the nerve and the muscle graft after RPNI formation. It is demonstrated that this interface can simultaneously record different signal information via the RPNI and the nerve, as well as stimulate them separately, inducing different responses. Furthermore, it is shown that this interface can record naturally evoked signals from a walking rabbit and use them to control a robotic leg. The long-term functionality and biocompatibility of this interface in rabbits are evaluated for up to 29 weeks, confirming its promising potential for enhancing prosthetic control.

Multidisciplinary Optimal Outcomes Reporting and Team Clinic Retention in Isolated Nonsyndromic Cleft Palate

OBJECTIVE

Optimal Outcomes Reporting was recently introduced to categorize outcomes after cleft palate repair. We seek to propose an expanded version of Optimal Outcomes Reporting and to determine if correlation exists between the expanded outcomes and persistence with team care follow-up through age 9.

DESIGN

Retrospective cohort study.

SETTING

Cleft team at large pediatric hospital.

PATIENTS

Patients with isolated nonsyndromic cleft palate (n = 83) born from 2001-2012.

MAIN OUTCOME MEASURES

Patients who continued to present at age 5 or greater were assessed for optimal outcomes. Optimal outcomes were: surgery - no fistula or velopharyngeal insufficiency; otolaryngology - no obstructive sleep apnea or signs of chronic middle ear disease; audiology - no hearing loss; speech-language pathology - no assessed need for speech therapy.

RESULTS

Of the 83 patients identified, 41 were assessed for optimal outcomes. Optimal outcome in any discipline was not associated with follow-up through age 9 (0.112 ≤ p ≤ 0.999). For all disciplines, the group with suboptimal outcomes had a higher proportion of patients from geographic areas in the most disadvantaged quartile of social vulnerability index, with the strongest association in the group with suboptimal speech outcome (OR 6.75, 95% CI 0.841-81.1).

CONCLUSIONS

Optimal outcomes and retention in team clinic were not statistically significantly associated, but clinically relevant associations were found between patients in the most disadvantaged quartile of social vulnerability and their outcomes. A patient-centered approach, including caregiver education about long-term care for patients with cleft palate, would allow for enhanced resource utilization to improve retention for patients of concern.

Limited Access to Alveolar Bone Graft Surgery Following Primary Cleft Lip and Palate Repair in Indonesia: A Questionnaire-Based Qualitative Study

INTRODUCTION

Cleft Lip and Palate is the most common craniofacial anomaly, and cleft lip and palate repair is widely performed. Alveolar cleft accompanies 75% of cleft lip cases and requires alveolar bone graft (ABG) surgery at mixed dentition age. However, studies on rates of ABG surgery are scarce.

OBJECTIVE

This study aims to investigate the low popularity of ABG and orthodontic care among patients with ABG history at Cleft and Craniofacial Centre, Cipto Mangunkusumo Hospital, Jakarta.

METHOD

A total of 771 patients had orofacial cleft surgeries throughout 2015 to 2021. A descriptive analysis of labioplasty, palatoplasty, and ABG surgeries was presented. Questionnaire-based qualitative analysis of ABG was obtained from the patient's guardians to evaluate the limitation and experience of conducting the surgery at our institution.

RESULTS

We distributed questionnaires to 13 patients with a history of ABG. ABG accounted for only 5% of total orofacial cleft surgeries. The average age of ABG surgery and orthodontic care initiation was 11 and 11.8 years old, respectively. About 82% had access to preoperative and postoperative orthodontic care; however, only 11% received PSO before 9 years old. The satisfaction rate was 100% and 75% in ABG patients with and without orthodontic care, respectively, reporting improved feeding, speech, teeth alignment, and esthetic result.

CONCLUSION

Orofacial cleft management requires a multistage, comprehensive, and multidisciplinary approach. The number of ABG surgeries is low in developing countries, attributed to unequal access to ABG and orthodontic care, suggesting that limitations of knowledge, geography, and economy play a big role in Indonesian healthcare.

A Cross-Sectional Study of the Nutritional Status of Infants with Orofacial Clefts in the First 6 Months of Life

OBJECTIVE(S)

To estimate nutritional status in a large cohort of infants with orofacial clefts in the US, overall and by cleft type from birth to 6 months of age.

STUDY DESIGN

We conducted a cross-sectional study in infants with orofacial clefts by examining growth by month between birth and 6 months of age. Infants with at least one weight measurement at a single US regional tertiary care pediatric hospital with an interdisciplinary cleft team between 2010 and 2020 were included. We calculated the average weight-for-age z scores and weight-for-length z scores. We calculated the proportion of infants underweight and wasting with z scores below -2 SDs monthly from birth to 6 months of age. We used t tests to compare the distribution of weight for age z-score and weight for length z-score among children with orofacial clefts to a normal distribution.

RESULTS

We included 883 infants with orofacial clefts. Compared with expected proportion of underweight infants (2.3%), a larger proportion of infants with orofacial clefts were underweight between birth and 1 month (10.6%), peaking between 2 and 3 months (27.1%), and remaining high between 5 and 6 months (16.3%). Compared with the expected proportion of infants with wasting (2.3%), a higher proportion of infants with orofacial clefts experienced wasting between birth and 1 month (7.3%), peaking between 2 and 3 months (12.8%), and remaining high between 5 and 6 months (5.3%). Similar findings were observed for all cleft types and regardless of comorbidities.

CONCLUSION(S)

A substantial proportion of infants with orofacial clefts compared with normative peers have malnutrition in the first 6 months of life in the US.

Relationship between achieving Sustainable Development Goals and promoting optimal care and prevention of birth defects globally

Birth defects affect eight million newborns annually worldwide. About 8% of global under-5 mortality is attributable to birth defects. The United Nations (UN) Sustainable Development Goals (SDGs) have set 17 global goals for human growth and development to be achieved by 2030 using multi-sectorial approaches. The third goal (SDG-3) focuses on ensuring healthy lives and promoting well-being; achieving SDG-3 improves birth defects care and prevention. However, we aimed to show how achieving other SDGs also influence optimal care and prevention of birth defects. SDGs focused on poverty reduction, access to nutritious food, universal health coverage, equitable education, gender equality, environment, inclusivity through infrastructure innovation, and strengthening social justice is crucial to addressing social determinants of health for individuals and families affected by birth defects. Understanding birth defects in the context of several relevant SDGs will allow practitioners, researchers, and policymakers to leverage the momentum generated by SDGs and make a case for commitment and allocation of funding and resources for advancing birth defects surveillance, care, and prevention. SDGs are built on principles of equity and social justice and we urge policy-makers to approach birth defects using various SDGs as a catalyst. The synergy between several SDGs helps to optimize birth defect outcomes and prevention. Our effort to present a more comprehensive look at various SDGs and their relationship with birth defects is parallel to several other health advocacy groups conducting a similar mapping exercise, thus bringing to the forefront millions of lives that are impacted by birth defects worldwide.

Inter-centre comparison of data on surgery and speech outcomes at 5 years of age based on the Swedish quality registry for patients born with cleft palate with or without cleft lip

BACKGROUND

The objective of the Swedish cleft lip and palate registry (CLP registry) is to promote quality control, research and improvement of treatment, by the comparison of long-term results. The aim was to compare data from the CLP registry among the six treatment centres, regarding data on surgery and speech outcomes at 5 years of age.

METHODS

The participants were 430 children born in Sweden from 2009 to 2014, with cleft palate with or without cleft lip and without known syndromes and/or additional malformations. The number of primary and secondary palatal surgeries up to 5 years of age, timing of the last primary palatal surgery, percentage consonants correct, percentage non-oral speech errors and perceived velopharyngeal competence at 5 years were assessed. Multivariable binary logistic regression adjusted for sex and cleft type was used to compare results between the six centres.

RESULTS

At one centre (centre 4), the palate was closed in one to three stages, and at the remaining centres in one or two stages. At centre 4, more children underwent a higher number of palatal surgeries, and the last primary palatal surgery was performed at a higher age. Children in centre 4 were also less likely to achieve ≥86% correct consonants (OR = 0.169, P = < 0.001), have no non-oral speech errors (OR = 0.347, P = < 0.001), or have competent or marginally incompetent velopharyngeal competence (OR = 0.244, P = < 0.001), compared to the average results of the other centres. No clear association between patient volume and speech outcome was observed.

CONCLUSIONS

The results indicated the risk of a negative speech result if the last primary palatal surgery was performed after 25 months of age. Whether the cleft in the palate was closed in one or two stages did not affect speech outcome. The Swedish CLP registry can be used for open comparisons of treatment results to provide the basis for improvements of treatment methods. If deviating negative results are seen consistently at one centre, this information should be acted upon by further investigation and analysis, making changes to the treatment protocol as needed.