Published online January 3, 2005
PEDIATRICS Vol. 115 No. 1 January 2005, pp. 78-82 (doi:10.1542/peds.2004-0860)
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Use of Active Surveillance to Validate International Classification of Diseases Code Estimates of Rotavirus Hospitalizations in Children

Vincent P. Hsu, MD, MPH*, Mary Allen Staat, MD, MPH{ddagger}, Nancy Roberts, MS{ddagger}, Carla Thieman, RN{ddagger}, David I. Bernstein, MD{ddagger}, Joseph Bresee, MD*, Roger I. Glass, MD, PhD* and Umesh D. Parashar, MBBS, MPH*

* Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
{ddagger} Division of Infectious Disease, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio


   ABSTRACT
TOP
 ABSTRACT
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Objective. National estimates of hospitalizations for rotavirus, the leading cause of acute gastroenteritis (AGE) in children, have been used to establish the need for rotavirus vaccines. A previous method directly estimated discharges by using the rotavirus-specific International Classification of Diseases (ICD) code, but this method has not been validated. Our study evaluated the sensitivity of the rotavirus ICD code among children hospitalized for AGE by using active surveillance for rotavirus at a tertiary children's hospital.

Design. We compared data for rotavirus-coded hospital discharges in 2000–2001 at Cincinnati Children's Hospital Medical Center with data on laboratory-confirmed cases of rotavirus obtained from active surveillance. We estimated additional rotavirus hospitalizations by extrapolating the proportion of rotavirus-positive results from active-surveillance cases to those with an unknown rotavirus status.

Results. Of 767 cases of AGE-related discharge codes, 103 (13%) were coded as rotavirus, 91% (94 of 103) of which were laboratory-confirmed diagnoses. Among all children discharged with an AGE-related illness, 260 (34%) were enrolled in active surveillance, of whom 155 (60%) tested positive for rotavirus. An additional 47 laboratory-confirmed rotavirus-case patients not enrolled in active surveillance yielded a total of 202 rotavirus cases and a maximum sensitivity of the rotavirus code of 47%. Extrapolation indicated that an additional 170 untested children might be rotavirus-positive, yielding a total of 372 rotavirus hospitalizations and a minimum sensitivity of the rotavirus code of 25%.

Conclusions. Measurement of rotavirus-coded hospital discharges alone seems to greatly underestimate the true burden of rotavirus-associated hospitalizations. The numbers of national rotavirus hospitalization discharges may be substantially greater than previously estimated.

Key Words: acute gastroenteritis • United States • child • surveillance • hospitalization • ICD codes • sensitivity • specificity

Abbreviations: AGE, acute gastroenteritis • NHDS, National Hospital Discharge Survey • ICD, International Classification of Diseases • CCHMC, Cincinnati Children's Hospital Medical Center • EIA, enzyme immunoassay

Rotavirus is the most common cause of acute gastroenteritis (AGE) in children worldwide1 and is estimated to cause between 350 000 and 873 000 deaths annually, most of which occur in developing countries.2–4 Although rarely fatal in the United States, rotavirus remains a major cause of severe dehydration and hospitalization in children, thus incurring substantial health care costs. Because of the tremendous global burden of rotavirus disease, vaccines against this pathogen are being developed and a licensed product may be available in the next few years. Thus, obtaining accurate estimates of the rotavirus disease burden are crucial to assess the need for rotavirus vaccines.

Previous estimates of rotavirus hospitalizations in the United States have been derived with data from the National Hospital Discharge Survey (NHDS), a 0.5% sample of all hospital discharges in the United States. The total number of patients discharged with an International Classification of Diseases5 (ICD) code for AGE is used as the baseline to estimate the proportion of these hospitalizations attributable to rotavirus.6–9 One estimation method, the winter residual excess method, calculates the difference between the seasonally higher numbers of diarrhea cases in the winter rotavirus season and lower numbers of summer AGE hospitalizations, when rotavirus is absent, to estimate annual rotavirus hospitalizations. Another method applies the monthly proportion of rotavirus cases detected among children hospitalized with diarrhea, a number obtained from a large rotavirus surveillance study done between 1974 and 1982,10 to the monthly number of AGE hospitalizations to derive the fraction of all AGE cases caused by rotavirus. A previous analysis found little difference in the estimated number of rotavirus cases using either method and arrived at the conclusion that ~55 000 children, or just under one third of all AGE discharges, were hospitalized with rotavirus each year.8 In 1992, an ICD code for rotavirus (008.61) was introduced, allowing direct estimates of the number of rotavirus hospitalizations. A study examining the validity of using direct estimates found that using the ICD code for rotavirus understated the true number of cases: data from 1993 to 1995 identified that ~27 000 discharges, or 16.5% of all AGE discharges, were coded annually as rotavirus.11 It was not clear whether patients with rotavirus discharge codes actually had laboratory-confirmed illness or whether the codes reflected the clinical impression of physicians seeing patients with diarrhea in the winter season.

Although direct estimates of rotavirus hospitalizations are believed to underestimate the true hospitalization burden, and previous indirect estimates were considered more valid, the completeness and accuracy of either the indirect or direct methods for estimation of rotavirus hospitalizations has not been assessed. In anticipation of the licensure of the first rotavirus vaccine in the United States, an active hospital-based diarrhea surveillance system was set up at Cincinnati Children's Hospital Medical Center (CCHMC) to monitor rotavirus trends and measure the impact of vaccine. The availability of this surveillance system, independent of routine discharge coding, allowed us to compare the specific coding practices at this institution with diagnoses based on laboratory-confirmed rotavirus tests. Our aim was to validate the rotavirus-specific ICD code, using 2 years of data from an active hospital rotavirus surveillance system and the hospital clinical rotavirus laboratory, to generate an accurate estimate of rotavirus hospitalizations.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Sources of Data
Hospital Discharge Data
We reviewed CCHMC hospital discharge data for January 1, 2000, through December 31, 2001, to select those records with specific codes for AGE in children 0 to 59 months old. AGE hospitalizations were defined as discharges for which an AGE code (ICD, 9th Revision) was assigned to 1 of the first 7 listed diagnoses. These codes included diarrhea of determined etiology (bacterial [001–005, excluding 003.2, and 008.0–008.5], parasitic [006–007, excluding 006.2–006.6], viral [008.6 and 008.8, including rotavirus (008.61)]) and diarrhea of undetermined etiology (009.0–009.3 and 558.9) (Table 1). Variables, including age, gender, length of hospital stay, inpatient versus short stay (<24 hours) status, and month of admission, were compiled and analyzed.


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  		TABLE 1. ICD-9 Codes of Children 0 to 59 Months Old Discharged From CCHMC With AGE, 2000–2001

 
Active Rotavirus Surveillance
We reviewed data from the CCHMC rotavirus surveillance system for the same period, 2000–2001, in which children 0 to 59 months old with community-acquired AGE were enrolled and screened for rotavirus according to described methods.12 In brief, each weekday morning a research nurse checked the daily hospital census report and nursing admission logs to identify admissions for AGE in children <5 years old. Children whose onset of AGE occurred after hospital admission, patients who were transferred from another hospital after an admission exceeding 48 hours, patients with AGE persisting >7 days before admission, and patients admitted with a primary diagnosis unrelated to AGE were not enrolled. Stool specimens were sent to a research laboratory and tested for rotavirus by using an enzyme immunoassay (EIA) (Rotaclone, Meridian Diagnostics, Cincinnati, OH). Results for patients enrolled in this surveillance study were not reported to the patient or their health care provider.

Hospital Clinical Laboratory
We reviewed CCHMC clinical laboratory data for the period of 2000–2001 to find results of rotavirus tests routinely ordered by health care providers for children 0 to 59 months old. This clinical laboratory system functions independently of the research laboratory used in the active surveillance activity. The clinical laboratory tests for rotavirus by using an EIA, and results are reported to the patient's health care provider.

Analysis
We first matched patients discharge records reporting AGE with a database containing EIA results of both the research and the clinical laboratories to determine which patients were tested for rotavirus. We defined a rotavirus hospitalization as any patient with AGE coded on the discharge record with a positive rotavirus test. The maximum sensitivity of the rotavirus discharge code to detect rotavirus hospitalizations was calculated by dividing the number of hospitalizations that were laboratory confirmed and coded as rotavirus by the total number of laboratory-confirmed rotavirus cases. To estimate the number of rotavirus infections in patients who had not been tested for rotavirus, we excluded from analysis hospitalizations among nonenrolled cases with characteristics that differed significantly from those enrolled in active surveillance. We then applied a seasonal-specific proportion of rotavirus-positive results from the active surveillance group to the remaining hospitalizations among the nonenrolled group to get an adjusted number of rotavirus hospitalizations. The minimum sensitivity of the rotavirus code was determined by dividing the total number of hospital discharges coded as rotavirus by the estimated total number of rotavirus hospitalizations. Rotavirus proportion estimates were applied to 1996–2000 NHDS data and compared with results of previous studies examining national rotavirus hospitalizations.


   RESULTS
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
In 2000–2001, 15 559 children <5 years old were hospitalized at CCHMC, and of these, 767 (4.9%) were assigned a discharge code for AGE. Of these 767 patients, 52% were not assigned a specific etiologic code for their illness, and 38% were assigned a viral discharge code, including 103 patients (13%) who were assigned a rotavirus code (Table 1). Of these patients discharged with AGE discharge codes, 386 (50%) had stool samples tested for rotavirus. The percentage of stools tested for rotavirus varied by AGE category; testing was done in 94% of those with a rotavirus-coded discharge but only in 44% that were coded as viral. Among discharges that had an unspecified etiology, the percentage ranged between 34% and 58% for presumed noninfectious and presumed infectious discharges, respectively. Of the 767 patients with AGE discharge codes, 260 children (34%) were enrolled in active surveillance, of which 171 (22%) were enrolled in active surveillance and had stool samples tested only in the research laboratory, and 89 (12%) had stool samples tested in both laboratories (Fig 1). The remaining 126 (16%) nonenrolled patients had stool samples tested only in the clinical laboratory.


Figure 1
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  		Fig 1. Venn diagram illustrating the relationship between AGE-coded discharges and sources of rotavirus test results (active surveillance and clinical laboratory).

 
Among the 386 children tested for rotavirus, 202 (52%) were rotavirus-positive. This number included 47% of patients tested in the clinical laboratory and 60% of those enrolled in active surveillance (Table 2). The overall unadjusted proportion of positive rotavirus tests among all discharges assigned an AGE code was 26% (202 of 767). We found the ICD code for rotavirus to be specific, with 97% (94 of 97) of patients with discharge codes for rotavirus confirmed to be rotavirus positive by laboratory testing. By contrast, the overall sensitivity of discharges coded as rotavirus to reflect patients with laboratory-confirmed disease was low: only 47% (94 of 202) of patients with rotavirus-positive tests were assigned a rotavirus code. The sensitivity of the rotavirus code was greater in the clinical laboratory group (79%) than in the group enrolled in active surveillance (35%), but it was lowest among the subgroup of those tested who were tested only in the active surveillance laboratory without duplicate testing in the clinical laboratory (13%; data not shown).


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  		TABLE 2. Proportion of Positive Rotavirus Tests and Measures of Validity by Rotavirus Test Source

 
Adjusted Rotavirus Estimates
Demographic characteristics of patients enrolled in active surveillance were compared with those of nonenrolled children to identify any selection bias and to determine if the results of active surveillance could be applied to the total population of patients seen for AGE (Table 3). The groups did not differ significantly by age group, gender, or race, but enrollment in active surveillance declined in the summer and fall (51% vs 27%). Children not enrolled in active surveillance were more likely to have a primary diagnosis that was not AGE (11% vs 1%), to be admitted as an inpatient (84% vs 16%), and to be admitted for a stay of ≥4 days (29% vs 7%). Of the 381 AGE hospital discharges that were not tested for rotavirus, 101 were excluded to adjust for differences in the position of the AGE code and length of hospital stay between the active surveillance group and nonenrolled group. Applying season-specific rotavirus proportions to the remaining hospital discharges estimated at an additional 170 AGE-related hospitalizations, and adding them to the 202 laboratory-confirmed tests, led us to calculate that 49% (372 of 767) of all AGE-coded hospitalizations are caused by rotavirus, which sets the minimum sensitivity of the rotavirus code at 25% (Table 2).


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  		TABLE 3. Characteristics of Children Enrolled in Rotavirus Active Surveillance Compared With Those Not Enrolled

 
National Estimates of Rotavirus Hospitalizations
During 1996–2000 in the United States, an annual average of 185 046 hospital discharges for children 0 to 59 months old were assigned a diagnosis code of AGE, as determined on the basis of NHDS data (Table 4). Multiplying this figure by the range of unadjusted and adjusted rotavirus proportions (26–49%) yielded an estimate of between 48 700 and 89 700 annual hospitalizations caused by rotavirus in the United States, a figure with boundaries that include the range of previous indirect estimates but is >3 times the direct estimate obtained by using the rotavirus-specific code noted above.


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  		TABLE 4. Published Studies Comparing National Estimates of AGE and Rotavirus Hospitalizations

 

   DISCUSSION
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
Interest in the use of rotavirus vaccines in the United States has rested in part on our ability to estimate accurately the true burden of rotavirus disease and related hospitalizations. This study examined the validity of past estimates of rotavirus hospitalizations and sought methods to improve future estimates by comparing data on hospital discharges for AGE and rotavirus with laboratory-confirmed data available through an AGE surveillance program and a hospital clinical laboratory. Our results provide several insights into the estimation process. First, among all children discharged with a diagnosis coded as AGE and who were also tested for rotavirus, 52% were positive for rotavirus. Second, the use of hospital discharge records coded as rotavirus provided a very specific marker for true rotavirus disease: 98% of discharge records coded specifically as rotavirus had a laboratory-confirmed diagnosis. However, hospital discharge records were coded as rotavirus in less than half of the confirmed rotavirus infections and only 25% of those estimated when detection rates from active surveillance were extrapolated to the total number of AGE hospitalizations. This is partly because of the fact that rotavirus test results were shared with providers only for tests performed in the clinical laboratory. It also reflects the observation that many providers do not test fecal specimens for rotavirus, because the findings do not alter the treatment course for AGE and testing incurs additional costs. In summary, the most accurate estimates of the number of rotavirus hospitalizations should rest on multiplying the number of AGE cases by the detection rates of rotavirus observed through a program of systematic active surveillance of fecal specimens. However, use of the rotavirus code seems to be very specific, and when rotavirus is coded on the discharge certificate, the diagnosis is usually confirmed in the laboratory.

The active surveillance system enrolled only one third of all children discharged with an AGE code but detected an additional 22% of all AGE cases for rotavirus testing that would not have been tested otherwise. Because weekday surveillance would be expected to detect ~70% of all AGE cases, other factors may also have contributed to a lower percentage of enrollment, such as exclusion of certain cases, failure to obtain consent, and poor predictive value on non-AGE admission diagnoses that were subsequently assigned AGE codes on discharge.

At CCHMC, the proportion of rotavirus-related AGE (52%) was greater than that estimated in the original classic study by Brandt et al10 in the United States. That study was conducted from 1974 to 1982, using electron microscopy as the diagnostic test, and detected rotavirus in 33% of children at a single children's hospital. With improved detection methods, EIA has been demonstrated to have sensitivities for rotavirus detection of ≥99% and higher sensitivity than direct electron microscopy.13,14 Another reason for our higher estimate may lie in the restriction of our analysis of the rotavirus proportion to discharges coded as AGE. In addition, by using immunoassays for rotavirus detection, researchers have found 39% to 56% of AGE cases in other countries (eg, Vietnam, China, Finland, and the United Kingdom) to be caused by rotavirus, and these findings are more consistent with the results of the current study.15–18 Consequently, estimates of the annual number of rotavirus hospitalizations derived by multiplying national data on hospital discharges for AGE by the fraction of these cases caused by rotavirus would need to be revised and increased in view of the findings of this and other surveys. In addition, previous outpatient estimates thought to be related to rotavirus diarrhea were also loosely derived using the proportion of rotavirus-related AGE to a large national database and would need to be reexamined.6,19 However, estimates of rotavirus-related mortality have been calculated by using the winter residual method6,20; thus, methods to evaluate outpatient visits and mortality caused by rotavirus needs additional evaluation.

This study has 2 major limitations. First, extrapolation of the proportion of rotavirus cases from the active surveillance group to an untested group, even after adjustment for known factors, does not take into account all differences that may exist between the 2 groups. We chose to extrapolate the active surveillance rotavirus proportion, because enrollment was theoretically more systematic for identifying AGE admissions. Increased sensitivity of active surveillance to increase rotavirus testing can give more accurate rotavirus hospitalization estimates. Second, CCHMC, as a single academic institution, may not be representative of the hospitals in the United States with pediatric admissions. Many factors including rotavirus prevalence, rotavirus laboratory testing capabilities and usage, specific hospital characteristics (size, location, whether academic or community), and specific coding practices of physicians within those hospitals will affect national estimates of the rotavirus burden.

Given that the sensitivity of the rotavirus-specific ICD code is limited, active surveillance for AGE and rotavirus disease remains an essential tool for an accurate estimation of the rotavirus burden. We found that after adjustment for AGE discharges that were not tested for rotavirus, the proportion of AGE caused by rotavirus was higher than estimated in previous studies. Future studies examining estimates of rotavirus hospitalizations should focus on increasing active hospital surveillance to all children with AGE or a proper systematic sample and extending surveillance to multiple hospitals in various geographic localities. Similar validation studies will allow policy makers in the United States and elsewhere to derive improved estimates of AGE caused by rotavirus and a better assessment regarding implementation of future rotavirus vaccines.


   FOOTNOTES
 
Accepted Jun 8, 2004.

Address correspondence to Vincent P. Hsu, MD, MPH, 685 Palm Springs Dr, Suite 2A, Altamonte Springs, FL 32701. E-mail: vhsu{at}att.net

Reprint requests to (R.I.G.) Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd, MS G-04, Atlanta, GA 30333. E-mail: rglass{at}cdc.gov

No conflict of interest declared.


   REFERENCES
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Bern C, Martinez J, de Zoysa I, Glass R. The magnitude of the global problem of diarrhea disease: a ten-year update. Bull World Health Organ. 1992;70 :705 –714[ISI][Medline]
  2. Miller MA, McCann L. Policy analysis of the use of hepatitis B, Haemophilus influenzae type b-, Streptococcus pneumoniae-conjugate and rotavirus vaccines in national immunization schedules. Health Econ. 2000;9 :19 –35[CrossRef][ISI][Medline]
  3. Institute of Medicine. Prospects for immunizing against rotavirus. In: New Vaccine Development: Establishing Priorities. Diseases of Importance in Developing Countries. Washington, DC: National Academy Press; 1986:308–318
  4. Parashar UD. Global illness and deaths caused by rotavirus disease in children. Emerg Infect Dis. 2003;9 :565 –572[ISI][Medline]
  5. Health Care Financing Administration. International Classification of Diseases, 9th Revision, Clinical Modification. 2nd ed. Washington, DC: US Public Health Service; 1980
  6. Glass RI, Kilgore PE, Holman RC, et al. The epidemiology of rotavirus diarrhea in the United States: surveillance and estimates of disease burden. J Infect Dis. 1996;174(suppl 1) :S5 –S11
  7. Ho MS, Glass RI, Pinsky PF, Anderson LJ. Rotavirus as a cause of diarrheal morbidity and mortality in the United States. J Infect Dis. 1988;158 :1112 –1116[ISI][Medline]
  8. Jin S, Kilgore PE, Holman RC, Clarke MJ, Gangarosa EJ, Glass RI. Trends in hospitalizations for diarrhea in United States children from 1979 through 1992: estimates of the morbidity associated with rotavirus. Pediatr Infect Dis J. 1996;15 :397 –404[CrossRef][ISI][Medline]
  9. Matson DO, Estes MK. Impact of rotavirus infection at a large pediatric hospital. J Infect Dis. 1990;162 :598 –604[ISI][Medline]
  10. Brandt CD, Kim HW, Rodriguez WJ, et al. Pediatric viral gastroenteritis during eight years of study. J Clin Microbiol. 1983;18 :71 –78[Abstract/Free Full Text]
  11. Parashar UD, Holman RC, Clarke MJ, et al. Hospitalizations associated with rotavirus diarrhea in the United States, 1993 through 1995: surveillance based on the new ICD-9-CM rotavirus-specific diagnostic code. J Infect Dis. 1998;177 :13 –17[ISI][Medline]
  12. Staat MA, Azimi PH, Berke T, et al. Clinical presentations of rotavirus infection among hospitalized children. Pediatr Infect Dis J. 2002;21 :221 –227[CrossRef][ISI][Medline]
  13. Dennehy PH, Gauntlett DR, Spangenberger SE. Choice of reference assay for the detection of rotavirus in fecal specimens: electron microscopy versus enzyme immunoassay. J Clin Microbiol. 1990;28 :1280 –1283[Abstract/Free Full Text]
  14. Lipson SM, Svenssen L, Goodwin L, Porti D, Danzi S, Pergolizzi R. Evaluation of two current generation enzyme immunoassays and an improved isolation-based assay for the rapid detection and isolation of rotavirus from stool. J Clin Virol. 2001;21 :17 –27[CrossRef][ISI][Medline]
  15. Nguyen VM, Nguyen VT, Huynh PL, et al. The epidemiology and disease burden of rotavirus in Vietnam: sentinel surveillance at 6 hospitals. J Infect Dis. 2001;183 :1707 –1712[CrossRef][ISI][Medline]
  16. Fang ZY, Yang H, Qi J, et al. Diversity of rotavirus strains among children with acute diarrhea in China: 1998–2000 surveillance study. J Clin Microbiol. 2002;40 :1875 –1878[Abstract/Free Full Text]
  17. Vesikari T, Rautanen T, Von Bonsdorff CH. Rotavirus gastroenteritis in Finland: burden of disease and epidemiological features. Acta Paediatr Suppl. 1999;88 :24 –30[CrossRef][Medline]
  18. Ryan MJ, Ramsay M, Brown D, Gay NJ, Farrington CP, Wall PG. Hospital admissions attributable to rotavirus infection in England and Wales. J Infect Dis. 1996;174(suppl 1) :S12 –S18
  19. Glass RI, Lew JF, Gangarosa RE, LeBaron CW, Ho MS. Estimates of morbidity and mortality rates for diarrheal diseases in American children. J Pediatr. 1991;118 :S27 –S33[CrossRef][ISI][Medline]
  20. Kilgore PE, Holman RC, Clarke MJ, Glass RI. Trends of diarrheal disease–associated mortality in US children, 1968 through 1991. JAMA. 1995;274 :1143 –1148[Abstract]
PEDIATRICS (ISSN 1098-4275). ©2005 by the American Academy of Pediatrics



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