Infantile gastroesophageal reflux in a hospital setting
© Baker et al; licensee BioMed Central Ltd. 2008
Received: 03 August 2007
Accepted: 27 March 2008
Published: 27 March 2008
Gastroesophageal reflux is a common diagnosis in infants. Yet, there is no information on the demographics of those hospitalized with reflux. The aim of this study is to describe the demographics of children with gastroesophageal reflux discharged from the hospital during the first two years of life.
Retrospective chart review of children aged 0–2 years discharged between January 1, 1995 and December 31, 1999 with a diagnosis of reflux documented in their hospital chart prior to 12 months of age.
Reflux was the seventh most common reason for hospitalization. About 50% of subjects with reflux had multiple hospitalizations. Of the 1,096 infants diagnosed with reflux about half were born prematurely. Reflux was the primary diagnosis for 21% of all infants; 10% of those born prematurely. The average length of stay for the subjects was longer than the hospital average. African Americans, 2.4% of the population, accounted for 29% of discharges. Caucasians, 86% of the population, were 66% of discharges. 21.8% of African Americans and 68.3% of Caucasians were diagnosed with reflux. 35% of mothers smoked, 27% worked and 48% had public insurance, compared to 22.2%, 57%, and 24% respectively of females in the general population.
Reflux is a common discharge diagnosis. Children who have primary reflux have longer than average hospital stays. About half had multiple admissions. Mothers of children with reflux are more likely to be less educated, receive public insurance, smoke, and be unemployed than the general female population in Western New York. Although African American children were disproportionately hospitalized, they were less likely to be diagnosed with reflux.
Gastroesophageal reflux, defined by the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition as the passage of gastric contents into the esophagus , is common in infants [2, 3]. Yet, there is no information on the demographics of children who have reflux and require hospitalization. Most often the clinical diagnosis of reflux and the decision to employ therapeutic interventions is made by clinicians based on signs and symptoms presented by the patient. Therefore, we used the diagnosis that clinicians assigned to their hospitalized patients to identify patients for inclusion in the study. For this report, we defined primary reflux as reflux that was the primary reason for hospitalization and secondary reflux as reflux that was not the primary reason for hospitalization.
We hypothesized that reflux is an important cause for hospitalizations for children ≤ 2 years of age, that reflux frequently occurs concomitantly with other diseases and that infants born prematurely (< 37 weeks gestation) who were admitted to the hospital with reflux had different characteristics than those who were born at term (≥ 37 weeks gestation). We also hypothesized that demographic data might identify children diagnosed with reflux who are at increased risk for hospitalization. This study was designed to describe the incidence, evaluation, and treatment of children with the most severe reflux, those requiring admission to the hospital, during the first two years of life. This manuscript reports on the demographics of the study children. The data did not allow us to determine the extent reflux contributed to the child's illness, only that it was present. Because the study contained thousands of data points for each category, this report focuses only on the demographic characteristics of the patients. Laboratory, therapeutic, financial and outcomes of the study patients will be presented in subsequent manuscripts.
Vomiting following gastrointestinal surgery
Feeding problems in the newborn
Choking due to food regurgitation
Using questionnaires from the literature as well as personal experience, a codebook was constructed to transform extracted data to numerical form. The following categories were covered in the codebook: demographics, clinical data, laboratory data and environmental data. However, only demographic data is reported herein.
Data Collection and Entry
A single individual (CR) reviewed each chart meeting the inclusion criteria. Data were entered into a Microsoft Access (Microsoft, Redmond, WA) database using the codebook. Ten percent of the charts (110) were also reviewed by one of a number of secondary reviewers. The variance in the interpretation of chart entries between the 2 reviewers was 0.1%.
Although special care was taken to identify information associated with fathers, very little data about fathers was contained in the charts. For many variables more than 50% of the charts were missing information. Therefore, information about fathers was excluded from the analysis.
Data were imported from the Microsoft Access database into the SAS (SAS Institute, Cary, NC) software package. Descriptive statistics were generated using frequency tables.
Where possible groups were compared using chi square test.
There were 98,320 births, 7,155 infants were born at < 37 weeks gestation, in Western New York (WNY) during the study period. For each county, the birth rate per 1,000 females ages 15–44 years as described by the NYSDOH  was stable. The largest difference over the 5 year period was 4 births per 1,000 females ages 15–44. The proportion of infants born at < 37 weeks gestation varied with county from a low of 9.7 to a high of 11.7%. The proportion of infants born at < 37 weeks gestation for the state of NY was 11.4%.
Ten most frequent discharge diagnosis 1995–1999
Percent of discharges1
Urinary Tract Infection
Description of hospitalized children with reflux
All subjects (N = 1096)1
≥ 37 weeks gestation (N = 543)
<37 weeks gestation (N = 538)
Reflux is primary diagnosis
3 or more
10 or more
Mean age at diagnosis of reflux (months)
5.9 ± 20.2
6.4 ± 21
4.4 ± 17.1
About half of the children discharged with a diagnosis of reflux were born at < 37 weeks gestation. Fewer children born prematurely had reflux as a primary diagnosis compared to infants born at term, OR = 0.21 (95% CI: 0.15–0.30). Infants born at < 37 weeks gestation had complicated hospitalizations and reflux was often only one of many problems. Children born at term had fewer complicating medical problems.
Frequency of primary diagnoses if not reflux
Infants born at ≥ 37 weeks gestation
Infants born at < 37 weeks gestation
Infections and Parasitic Diseases
Endocrine, Nutritional, and Metabolic. Immunity
Nervous System and Sense Organs
Conditions in the Perinatal Period
Symptoms, Signs, and Ill Defined Conditions
Injury and Poisonings
Unknown or missing
Race in Western New York and of children hospitalized with reflux during the study period
Population of 8 counties N (% of total)
Hospital admissions ≤ 2 years
Study patients N (%)
Study patients ≥ 37 weeks gestation and reflux N (%)
Study patients < 37 weeks gestation and reflux N (%)
Parental smoking and reflux
Population1 N (%)
Reflux N (%)
Reflux ≥ 37 w N (%)
Reflux <37 w N (%)
Mother's Education (%)
Population in WNY1
Reflux ≥ 37 w
Reflux < 37 w
Mothers in labor force (%)
Labor force in WNY, ≥ 16 years of age1
Reflux ≥ 37 weeks
Reflux < 37 weeks
Discharges ≤ 2 y
Reflux ≥ 37 w
Reflux < 37 w
This is the first report on the demographics of children with reflux who are sick enough to be hospitalized.
WNY experienced little population flux over the study years and this allowed for an unusually accurate means of extrapolating data. For the purposes of this study WNY includes eight counties: Allegheny, Cattaragus, Chautauqua, Erie, Genesee, Niagara, Orleans, and Wyoming. This is an area bounded on the south by the Pennsylvania state border, on the north by Lake Ontario and on the west by Lake Erie. Because WCHOB serves as the regional center of WNY, and it is the only hospital in the described area that has designated pediatric beds, it is possible to estimate complication rates and rates of medical and surgical therapy for reflux. WCHOB is a 318 bed freestanding pediatric hospital that was established in 1892. It is the pediatric teaching hospital for the State University of New York School of Medicine and Biomedical Sciences and is the only pediatric in-patient facility in WNY. WCHOB is the only facility that offers testing for reflux, including pH probes, scintigraphy, gastrointestinal x-ray, esophageal motility and upper endoscopy. WCHOB is the only major pediatric surgery center in the area that offers laproscopic fundoplication for infants with severe complications of reflux. Therefore, virtually all infants from WNY with severe reflux were evaluated and treated at WCHOB.
For this study we relied on the discharge diagnosis to identify the patients.
Discharge diagnosis that are deemed the reason for hospitalization are recorded. In a systematic review of studies comparing routine discharge statistics the coding of discharge diagnosis accuracy on average was found to be high  especially for operations and procedures, less so for routine hospital information.
This study shows that a large proportion of children ≤ 2 years of age in WNY are diagnosed with reflux severe enough to result in hospitalization, or contribute to hospitalization. The NYSDOH estimates discharge rates for asthma, gastroenteritis and otitis media (discharges/10,000/year). During the duration of the study the mean rate of discharges for the 8 county area for children ≤ 2 years was 11.9, 6.7, and 1.7 for asthma, gastroenteritis and otitis media respectively. The discharge rate for reflux was 1.4, less than that for asthma or gastroenteritis, but comparable to otitis media. Both otitis media and reflux are common in children under 2 years of age and are usually minor illnesses. Nevertheless our results show that the diagnosis of reflux has a major impact on rates of hospitalization for children ≤ 2 years of age.
The average length of stay for children with a primary diagnosis of reflux only was longer than the average for the hospital as a whole during this time. Approximately 50% of the study subjects required more than one hospitalization and approximately 30% required three or more. This suggests that children with reflux are frequent users of in patient hospital services.
We identified some differences between infants who were born prematurely and those born at term. Of the children discharged with reflux, about half were born prematurely and reflux was the primary diagnosis for about 10% compared to about 20% for those born at term. Children born prematurely often have multiple medical problems and reflux may not be the most severe of those problems. There was no difference between infants born < 37 weeks and ≥ 37 weeks for the number of hospital discharges, mean age at diagnosis of reflux, sex, birth order or length of time vomiting was present before diagnosis.
The population in WNY is predominately Caucasian (86%), 2.4% of the population is African American (AA). Twenty-nine percent of AA children, 3 times the proportion of AA in the population, were discharged from the hospital, but less than 3 times the proportion of AA were discharged from the hospital with a diagnosis of reflux
It appears there is more reflux requiring hospitalization in AA children than in Caucasian children when hospital discharges are compared to the racial make up of the community. However, proportionately, AA discharges far exceed Caucasian discharges. Comparing AA children discharged with a diagnosis of reflux to total AA admissions and Caucasian children discharged with a diagnosis of reflux to total Caucasian discharges, AA are half as likely to be discharged for reflux as Caucasian. This observation is consistent with that of Nazer, et al  who showed that based on Ph probe data Caucasian infants have a significantly higher incidence of reflux than AA infants. The disproportionate number of AA discharged from the hospital might be explained by a different frequency of some diseases, different use of medical facilities, socioeconomic factors, or other unidentified factors. Our data does not permit us to discriminate among the possibilities.
Too few of the medical records documented the education level of mothers of infants born at ≥ 37 weeks to comment. But, compared to the area population, a disproportionate number of mothers of infants born at < 37 weeks completed a high school education or had any college education. Luo et al  observed increasingly higher rates of preterm birth in mothers with lower levels of education. Our data did not permit us to determine if the lower education of the mothers of infants born at <37 weeks gestation who had reflux was related to reflux or prematurity
In 1997, 23% of the US population and 23% of the New York State population, 25.1% of men and 22.2% of women smoked [10, 11]. Despite an aggressive antismoking stance, the proportion of people who smoke in New York state ranged from 22.5 to 22.3 from 1990 through 2000 . Smoking itself is associated with an increased risk of premature births . Passive smoking may be a risk factor for infant reflux. Tobacco smoke induces lower esophageal sphincter relaxation  and Alaswad et al  showed a strong correlation between esophageal pH and environmental smoke exposure in infants who presented with apparent life-threatening events. However, Martin et al  showed no association between environmental smoke and infant spilling. While this data does not permit a robust conclusion about the association of smoking and reflux in children less than 2 years, the disproportionate numbers of mothers who smoke and whose children have reflux is remarkable.
Compared to national insurance data all children discharged from WCHOB were more likely to have medical insurance. However, about 50% of the children in WNY had public insurance compared to about 25% nationally. There was no difference among all discharges of children ≤ 2 years, or those with reflux in WNY. The high proportion of children in this study who had health insurance likely reflects NY State's aggressive program to provide health insurance for children.
This is the first time that demographic data on children hospitalized with a diagnosis of gastroesophageal reflux has been studied and the data show that reflux is a common discharge diagnosis for hospitalized children ≤ 2 years of age. Frequently reflux is not the primary discharge diagnosis. Children for whom the primary diagnosis is reflux have longer than average hospital stays and about half had multiple hospital admissions during the study period. Those born at < 37 weeks were less likely to have reflux as a primary diagnosis. Mothers of children with reflux are more likely to have less education, to receive public insurance, smoke more, and be unemployed than the average female in the general population in WNY. AA children ≤ 2 years were disproportionately discharged from the hospital compared to Caucasian children. Once admitted to the hospital AA were less likely to have reflux as a diagnosis than Caucasians. This study raises questions about which children with reflux are hospitalized and why and suggests that some demographic factors may make a child more likely to be hospitalized. It is also possible that these factors place the child at risk for severe reflux.
The work reported in this manuscript was supported by Grant Number E11/CCE220663-01 from the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention played no role in the collection of data, analysis, interpretation of data, writing of the manuscript or in the decision to submit the manuscript for publication.
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