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Augmentation Cystoplasty Rates at Children’s Hospitals in the United States: A Pediatric Health Information System Database Study
Augmentation Cystoplasty Rates at Children’s Hospitals in the United States: A Pediatric Health Information System Database Study Thomas S. Lendvay,* Charles A. Cowan, Michael M. Mitchell,† Byron D. Joyner† and Richard W. Grady From the Children’s Hospital and Regional Medical Center and Departments of Urology and Pediatric Medicine (CAC), University of Washington School of Medicine, Seattle, Washington
Purpose: We identified augmentation cystoplasty rates in children with spina bifida at children’s hospitals enrolled in the Pediatric Health Information System database. Materials and Methods: The Pediatric Health Information System database tabulates demographic and diagnostic patient data from 35 children’s hospital centers in the United States. Between October 1999 and September 2004 we extracted data on 0 to 19-year-old patients with International Classification of Diseases-9 diagnosis codes for spina bifida. The International Classification of Diseases-9 procedure code for augmentation cystoplasty was cross-referenced with these patients to determine the total number of patients with augmentation, total population augmentation rates and individual institution rates of bladder augmentation. Results: Staff at enrolled pediatric medical centers submitted inpatient data accounting for 9,059 beds servicing an aggregate metropolitan population of 82 million individuals. In the 5-year period 12,925 unique spina bifida patient encounters were identified, including 665 patients who underwent augmentation cystoplasty. The mean 5-year institutional number of augmentations performed in children with spina bifida was 20 (range 1 to 121) and the mean annual number of augmentations performed per institution was 4. The overall augmentation rate at 33 hospitals contributing data for the full years 2000 to 2003 was 5.4% (range 0.5% to 16.3%, p ⬍0.0001). The male-to-female ratio of those who underwent augmentation was 1:1.2. Median length of stay in children with augmentation was 7 days (mean 9). The median age of children with augmentation was 10.4 years, that is 11.3 years in boys and 9.8 years in girls. The difference in mean age was statistically significant (p ⬍0.003). At institutions where 10 or more augmentations were performed in 5 years (mean 27) mean patient age at operation was 10.1 years. This was significantly younger than the mean patient age of 12.3 years at hospitals where fewer than 10 augmentations (mean 5) were done in 5 years (p ⬍0.05). Conclusions: Clinical management for neurogenic bladder conditions has evolved to emphasize nonoperative management. Several studies suggest that aggressive early intervention improves bladder compliance and may protect renal function. However, results from the Pediatric Health Information System database demonstrate no change in augmentation rates during this time and they demonstrate significant interinstitutional variability. To our knowledge this represents the largest series of augmentation cystoplasty in children with spina bifida to date. Key Words: bladder, spinal dysraphism, abnormalities, urinary incontinence
hildren with spina bifida represent a complex patient population that requires multidisciplinary lifelong care. Almost universally these children experience neurogenic urinary bladder dysfunction, while some require aggressive treatment to protect the upper tract and afford them a high degree of independence and social well-being. Greater than 90% of patients with spinal dysraphisms have lower urinary tract dysfunction.1 Although the incidence of spina bifida has decreased secondary to increased awareness of folic acid in neural tube development and the increase in pregnancy termination,2 the severity of neurourological disease in the population has remained relatively unchanged. Upper urinary tract deterioration and incontinence are the most frequent urological sequelae of myelodysplasia.3
C
Study received institutional review board approval. * Correspondence: Children’s Hospital and Regional Medical Center, 4800 Sand Point Way, Northeast, Seattle, Washington 98105. † Financial interest and/or other relationship with Qmed.
0022-5347/06/1764-1716/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION
Half of these patients experience bladder-sphincter dyssynergia and 18% to 70% of children with spina bifida demonstrate decreased bladder compliance on urodynamics.4 Renal damage from high pressures due to urethral sphincter dyssynergia and bladder hyperreflexia5 as well as frequent urinary tract infections leads to significant morbidity. The combined renal and bladder sequelae place these children at risk for end stage renal disease and the social stigma of constant urinary wetting. Before the advent of clean intermittent catheterization popularized by Diokno and Lapides,6 and the consistent use of anticholinergics patients experienced continuous urinary incontinence and/or retention, and many required urinary diversion. After the introduction of intermittent catheterization enterocystoplasty became a useful adjunct to improve bladder compliance and preserve renal function. More recently investigators noted that early aggressive nonsurgical management may protect renal function and perhaps prevent the need for augmentation cystoplasty.7–9 However, to
1716
Vol. 176, 1716-1720, October 2006 Printed in U.S.A. DOI:10.1016/S0022-5347(06)00615-X
AUGMENTATION CYSTOPLASTY AT CHILDREN’S HOSPITALS IN UNITED STATES our knowledge no large series in the literature has clearly shown that augmentation cystoplasty rates have decreased in the face of comprehensive nonsurgical management. Collaborative studies have sought to increase research study power and determine clinical practice pattern standards but these studies present logistical hurdles, especially in complex patient populations such as those with myelodysplasia. Prompted by shrinking health care resources and an increasing desire to improve medical care by offering practice standards a number of patient care databases have been created by various health care organizations. The PHIS database was created to allow enrolled hospitals a means of assessing their practices as they relate to other institutions. The database has been used to demonstrate practice pattern variability in treatment for appendicitis, bronchiolitis and asthma, and quantify the impact of adult care performed at pediatric institutions.10 –14 We used the database to analyze augmentation cystoplasty practices across the country in patients with spina bifida. MATERIALS AND METHODS The PHIS Database Data in this study were extracted from the PHIS database, which was created by a business alliance of noncompeting, freestanding children’s hospitals in the United States. The first institution began submitting data in 1992. Since then, 35 medical centers have pooled data, submitting 125 data elements on each patient encountered. The data have been collated on several categories of patient visits, including inpatient admissions, medical short stays, ambulatory surgery visits and emergency department visits, allowing a comparative tool to promote improved medical care and resource use. Of the 20 major metropolitan areas in the United States 17 are represented in this data base. The National Association of Children’s Hospitals and Related Institutions estimated that there are 50 to 55 freestanding pediatric general acute care hospitals in the United States. Of these hospitals 70% submit data to PHIS.10 More than 20,000 physicians providing for more than 250,000 pediatric admissions yearly yield comprehensive data from which outcomes analysis and resource management can be studied. Data include demographics, clinical conditions, payer and cost data, treating physicians and severity indexes using the grouping technology All-Patient Refined Diagnosis Related Groups. Data are submitted electronically to a warehouse in Ann Arbor, Michigan administered by a health care business intelligence company.15 Online data encompass a rolling 5-year period and they are updated every calendar quarter. After a new quarter is added the first quarter is archived with the rest of the data, which date back to 1992. Database Interrogation After institutional review board approval was granted we extracted data on all 0 to 19-year-old patients encountered as inpatient visits between October 1, 1999 and September 30, 2004 with the International Classification of Diseases-9 diagnosis codes for spina bifida (741.9 and 741.0).16 Results were blinded as to the identity of the hospitals, which is consistent with the policies of PHIS and the health care business intelligence company. After the patient pool was created we cross-referenced these patients with the Interna-
1717
tional Classification of Diseases-9 procedure code for augmentation cystoplasty (57.87). Statistical analysis was performed using Student’s paired t test and significance was considered at p ⬍0.05. RESULTS Inpatient data were submitted from 35 children’s medical centers during the study period, accounting for 9,059 hospital beds and servicing an aggregate metropolitan population of 82 million individuals. During the 5-year period 12,925 unique spina bifida patient encounters were identified, including 665 patients who underwent augmentation cystoplasty. Because hospital enrollment is rolling, complete data for analysis were submitted from only 33 institutions during the 4-year period of 2000 to 2003. This represented 9,861 spina bifida patient encounters and 534 augmentation cystoplasties. The male-to-female ratio in children with augmentation was 1:1.2. Median LOS in children with augmentation was 7 days (mean 9). Median preoperative LOS was 1 day. There was no statistically significant difference between the sexes for LOS (p ⫽ 0.51). Median age at augmentation was 10.4 years, that is 11.3 years in boys and 9.8 years in girls. The difference in mean age was statistically significant (p ⬍0.003). At medical centers with pediatric urology fellowships there was an average of 30 augmentation cystoplasties per 5 years in children with spina bifida, while the average number per 5 years at nonfellowship institutions was 14. LOS at fellowship and nonfellowship centers was not statistically different (9.7 vs 8.4 days, p ⫽ 0.24) Likewise the severity index (a weighted factor that considers the number of diagnoses attached to a particular patient) in patients at augmentation was not statistically different between fellowship and nonfellowship programs (p ⫽ 0.5). At institutions where 10 or more augmentations (mean 27) were performed in 5 years mean patient age at operation was 10.1 years. This was significantly younger than at hospitals where fewer than 10 augmentations (mean of 5) were performed in 5 years, that is 12.3 years (p ⬍0.05). LOS at these centers was not statistically different at a mean of 9 days at hospitals with 10 or greater augmentations per 5 years compared to 8.5 days at those with less than 10 augmentations per 5 years (p ⫽ 0.54). Between 2000 and 2003 the rate of augmentation cystoplasty remained the same with a total mean multi-institutional rate of 5.4%, that is 5.3%, 5.5%, 5.4% and 5.4% for each year, respectively (fig. 1). Data also showed tremendous individual institutional variability in the number of patients with spina bifida encountered and in the rate of augmentation cystoplasty in these patients. The difference between the highest and the lowest mean 4-year individual institutional augmentation rate was statistically significant (0.5% to 16.3%, p ⬍0.0001, figs. 2 and 3). There appeared to be little correlation in whether cystoplasty was performed at a higher or lower rate at centers where more children with spina bifida were encountered. DISCUSSION Greater than 90% of patients with spinal dysraphisms have lower urinary tract dysfunction.1 Although the incidence of spinal dysraphisms has decreased due to increased aware-
1718
AUGMENTATION CYSTOPLASTY AT CHILDREN’S HOSPITALS IN UNITED STATES
FIG. 1. Average multi-institutional yearly augmentation rate in children with spina bifida.
ness of the importance of folic acid in neural tube development and the increase in pregnancy termination, the severity of urological disease in the population has remained the same. In the last decade several clinical studies have suggested that aggressive early nonoperative intervention may help protect children and lessen the need for augmentation cystoplasty. Kaefer et al noted a decrease in the need for augmentation in patients treated with early intermittent catheterization and anticholinergic therapy compared to that in observed historical controls with similar urodynamics profiles.7 However, there is controversy regarding the initiation of these measures and whether early or late management has any impact on the ultimate need for bladder augmentation.7,17 In addition, data on long-term sequelae in patients with enteric augmentations to the urinary tract demonstrate that considerable morbidity is associated with this practice.18,19 However, these results stem from small, single institutional studies and little is known about actual trends in management and practice pattern variability. The lack of available data in the literature assessing long-term outcomes in patients with spina bifida has not allowed clarity. More stringent and reproducible clinical and urodynamic criteria are required to determine whether some children
FIG. 2. Number of augmentation cystoplasties in children with spina bifida vs number of unique spina bifida inpatient visits at given institution from 2000 to 2003.
FIG. 3. Augmentation cystoplasty rate per institution from 2000 to 2003.
may be better served by nonsurgical management. Although some experts have suggested that we can manage these cases by a lower rate of bladder augmentation, we could not detect a decreasing trend of augmentation on a large, multiinstitutional level. We noted that the rate of augmentation cystoplasty remained the same during the study period. Expanding the analysis for an extended period may help clarify longer term patterns. We noted a trend toward a greater number of augmentations performed at fellowship training centers. This may be explained by the academic and tertiary nature of the program. However, significant variation exists even between academic medical center practices throughout the country. We could not observe any significant difference of patient severity between nonfellowship and fellowship centers. Also, children underwent augmentation at an earlier age at higher volume centers. Several explanations may be possible for this trend. Perhaps clinician experience allows earlier recognition of the need for augmentation. Conversely this could be explained by the ability of staff at institutions with multidisciplinary spina bifida clinics to maintain more frequent patient followup and act sooner on changes in voiding dysfunction and renal deterioration. A higher rate of augmentation could reflect a lack of urological input until it is too late or a volume of patients overwhelms the available resources. We also noted a difference in age at augmentation between girls and boys. This may be explained by social influences and the degree of maturity. At the preadolescent age girls mature cognitively more rapidly than boys and they may be capable of understanding the logistics of intermittent catheterization, augmentation irrigation and maintenance, while also being more socially aware of incontinence at an earlier age. Patients confined to a wheelchair may find it to be technically more difficult to catheterize through the female urethra, prompting a demand from patients and caregivers to intervene sooner. Also, girls achieve menarche near the time of the median augmentation age of 9.8 years and it may be easier to catheterize through an abdominal stoma after menstruation cycles occur.
AUGMENTATION CYSTOPLASTY AT CHILDREN’S HOSPITALS IN UNITED STATES The use of multi-institutional databases to assess outcomes enables observers to make conclusions based on high powered data, while minimizing the degree of influence from statistical noise. Newman11 and Ponsky10 et al used PHIS to analyze practice pattern variability in the treatment of appendicitis by analyzing data from 30 hospitals evaluating 3,393 children. They determined positive and nonpositive operative and nonoperative rates, described the financial charge per patient, assessed rehospitalization rates and looked at the use of laparoscopy, antibiotics, anti-emetics and various imaging modalities. They concluded that there was significant practice pattern variability and no best practices existed to guide clinicians to provide highly successful and efficient care. They suggested that future multi-institutional collaboration might allow a quality initiative to share and adopt improved practice patterns for antibiotic, anti-emetic and analgesic regimens. Goodman et al used the PHIS database to describe the impact that adult patients have on children’s medical centers. They noted that among 6 institutions 3,863 patients 18 to 64 years old incurred $134.5 million of charges during a total of 5,051 hospital encounters between 1994 and 1999. This demonstrated how powerful a tool PHIS was at describing a specific patient population. From these data they were able to identify the 3 most common diagnoses in these adults, that is cystic fibrosis, mental retardation or cerebral palsy and congenital heart disease. They concluded that perhaps a new subspecialty geared specifically at adult patients at childhood diseases should be created to assume care of these unique patients.14 Use of the PHIS database to assess outcomes analysis contains inherent weaknesses. For example, the database relies on proper coding from each institution and it may be influenced by variability in coding practices among physicians and coders alike. In addition, there is selection bias, in that some institutions enrolled in PHIS may be tertiary referral centers, while others may function as community hospitals servicing the local region, and there may be sampling bias, in that PHIS does not track all hospitals, so that the database is not a population survey. Also, some institutions are academic and affiliated with universities, and have residency and fellowship training responsibilities, and by their nature medicine may be practiced differently there than at private, nonacademic centers. In addition, geographic and regional variations may have a role in selection bias, yielding the disparate patient demographics encountered. Future studies exploiting multiple databases will enable us to study disease as more of a population or census based study as we are able to capture the majority of children in the United States. A cohort study following children from birth through childhood may aid in determining the overall risk of requiring augmentation cystoplasty and case-control studies may define a difference in augmentation risk by era in matched nonoperated controls. Likewise identifying peer hospitals that share similar profiles with regard to size, referral patterns, managed care markets and academic pursuits will enable us to define centers specializing in specific patient diseases and create a benchmark from which other institutions may practice.
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CONCLUSIONS There is significant practice pattern variability in managing the urinary tract of children with spina bifida. We did not identify a trend toward decreasing surgical intervention and there does not appear to be a trend toward surgical intervention at centers that see more children with spina bifida. It remains to be seen if more aggressive nonoperative management of patients with spina bifida translates into decreasing bladder augmentation rates. Expanding the analysis to multiple databases and tracking patients in a prospective manner will allow us to develop practice standards to ensure optimal patient care. ACKNOWLEDGMENTS The PHIS database was created at Child Health Corp., Shawnee Mission, Kansas. Data are submitted electronically to Solucient LLC, Evanston, Illinois.
Abbreviations and Acronyms LOS ⫽ length of stay PHIS ⫽ Pediatric Health Information Systems REFERENCES 1.
2.
3. 4.
5.
6. 7.
8.
9.
10.
11.
Bauer, S. B.: Neurogenic dysfunction of the lower urinary tract in children. In: Campbell’s Urology, 7th ed. Edited by P. C. Walsh, A. B. Retik, E. D. Vaughan, Jr. and A. J. Wein. Philadelphia: W. B. Saunders Co., chapt. 65, pp. 2019-2054, 1998 Flood, T., Brewster, M., Harris, J. et al: Spina bifida incidence at birth—United States, 1983–1990. MMWR Morb Mortal Wkly Rep, 41: 497, 1992 Smith, E. D.: Urinary prognosis in spina bifida. J Urol, 108: 815, 1972 Bauer, S. B., Hallett, M., Khoshbin, S., Lebowitz, R. L., Winston, K. R., Gibson, S. et al: Predictive value of urodynamic evaluation in newborns with myelodysplasia. JAMA, 252: 650, 1984 Galloway, N. T. M., Mekras, J. A., Helms, M. and Webster, G. D.: An objective score to predict upper tract deterioration in myelodysplasia. J Urol, 145: 535, 1991 Diokno, A. C. and Lapides, J.: Oxybutynin: a new drug with analgesic and anticholinergic properties. J Urol, 108: 307, 1972 Kaefer, M., Pabby, A., Kelly, M., Darbey, M. and Bauer, S. B.: Improved bladder function after prophylactic treatment of the high risk neurogenic bladder in newborns with myelomeningocele. J Urol, 162: 1068, 1999 Geraniotis, E., Koff, S. A. and Enrile, B.: The prophylactic use of clean intermittent catheterization in the treatment of infants and young children with myelomeningocele and neurogenic bladder dysfunction. J Urol, 139: 85, 1988 Edelstein, R. A., Bauer, S. B., Kelly, M. D., Darbey, M. M., Peters, C. A. and Atala, A.: The long-term urological response of neonates with myelodysplasia treated proactively with intermittent catheterization and anticholinergic therapy. J Urol, 154: 1500, 1995 Ponsky, T., Huang, Z., Kittle, K., Eichelberger, M., Gilbert, J., Brody, F. et al: Hospital and patient-level characteristics and the risk of appendiceal rupture and negative appendectomy in children. JAMA, 292: 1977, 2004 Newman, K., Ponsky, T., Kittle, K., Dyk, L., Throop, C., Gieseker, K. et al: Appendicitis 2000: variability in practice, outcomes, resource utilization at thirty pediatric hospitals. J Pediatr Surg, 38: 372, 2003
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Christakis, D., Cowan, C., Garrison, M., Molteni, R., Marcuse, E. and Zerr, D.: Variation in inpatient diagnostic testing and management of bronchiolitis. Pediatrics, 115: 878, 2005 13. Todd, J., Bertoch, D. and Dolan, S.: Use of a large national database for comparative evaluation of the effect of a bronchiolitis/viral pneumonia clinical care guideline on patient outcome and resource utilization. Arch Pediatr Adolesc Med, 156: 1086, 2002 14. Goodman, D., Mendez, E., Throop, C. and Ogata, E.: Adult survivors of pediatric illness: the impact on pediatric hospitals. Pediatrics, 110: 583, 2002 15. Solucient. Available at http://www.solucient.com/aboutus/ aboutus.shtml. Accessed May 27, 2005
16.
Hart, A. and Hopkins, C.: International Classification of Diseases ICD-9-M Expert. Salt Lake City, Utah: Ingenix, 2004 17. Teichman, J. M., Scherz, H. C., Kim, K. D., Cho, D. H., Packer, M. G. and Kaplan, G. W.: An alternative approach to myelodysplasia management: aggressive observation and prompt intervention. J Urol, 152: 807, 1994 18. Mitchell, M. and Piser, J.: Intestinocystoplasty and total bladder replacement in children and young adults: follow-up in 129 cases. J Urol, 138: 579, 1987 19. Hafez, A., McLorie, G., Gilday, D., Laudenberg, B., Upadhyay, J., Bagli, D. et al: Long-term evaluation of metabolic profile and bone mineral density after ileocystoplasty in children. J Urol, 170: 1639, 2003
Purpose: We identified augmentation cystoplasty rates in children with spina bifida at children’s hospitals enrolled in the Pediatric Health Information System database. Materials and Methods: The Pediatric Health Information System database tabulates demographic and diagnostic patient data from 35 children’s hospital centers in the United States. Between October 1999 and September 2004 we extracted data on 0 to 19-year-old patients with International Classification of Diseases-9 diagnosis codes for spina bifida. The International Classification of Diseases-9 procedure code for augmentation cystoplasty was cross-referenced with these patients to determine the total number of patients with augmentation, total population augmentation rates and individual institution rates of bladder augmentation. Results: Staff at enrolled pediatric medical centers submitted inpatient data accounting for 9,059 beds servicing an aggregate metropolitan population of 82 million individuals. In the 5-year period 12,925 unique spina bifida patient encounters were identified, including 665 patients who underwent augmentation cystoplasty. The mean 5-year institutional number of augmentations performed in children with spina bifida was 20 (range 1 to 121) and the mean annual number of augmentations performed per institution was 4. The overall augmentation rate at 33 hospitals contributing data for the full years 2000 to 2003 was 5.4% (range 0.5% to 16.3%, p ⬍0.0001). The male-to-female ratio of those who underwent augmentation was 1:1.2. Median length of stay in children with augmentation was 7 days (mean 9). The median age of children with augmentation was 10.4 years, that is 11.3 years in boys and 9.8 years in girls. The difference in mean age was statistically significant (p ⬍0.003). At institutions where 10 or more augmentations were performed in 5 years (mean 27) mean patient age at operation was 10.1 years. This was significantly younger than the mean patient age of 12.3 years at hospitals where fewer than 10 augmentations (mean 5) were done in 5 years (p ⬍0.05). Conclusions: Clinical management for neurogenic bladder conditions has evolved to emphasize nonoperative management. Several studies suggest that aggressive early intervention improves bladder compliance and may protect renal function. However, results from the Pediatric Health Information System database demonstrate no change in augmentation rates during this time and they demonstrate significant interinstitutional variability. To our knowledge this represents the largest series of augmentation cystoplasty in children with spina bifida to date. Key Words: bladder, spinal dysraphism, abnormalities, urinary incontinence
hildren with spina bifida represent a complex patient population that requires multidisciplinary lifelong care. Almost universally these children experience neurogenic urinary bladder dysfunction, while some require aggressive treatment to protect the upper tract and afford them a high degree of independence and social well-being. Greater than 90% of patients with spinal dysraphisms have lower urinary tract dysfunction.1 Although the incidence of spina bifida has decreased secondary to increased awareness of folic acid in neural tube development and the increase in pregnancy termination,2 the severity of neurourological disease in the population has remained relatively unchanged. Upper urinary tract deterioration and incontinence are the most frequent urological sequelae of myelodysplasia.3
C
Study received institutional review board approval. * Correspondence: Children’s Hospital and Regional Medical Center, 4800 Sand Point Way, Northeast, Seattle, Washington 98105. † Financial interest and/or other relationship with Qmed.
0022-5347/06/1764-1716/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION
Half of these patients experience bladder-sphincter dyssynergia and 18% to 70% of children with spina bifida demonstrate decreased bladder compliance on urodynamics.4 Renal damage from high pressures due to urethral sphincter dyssynergia and bladder hyperreflexia5 as well as frequent urinary tract infections leads to significant morbidity. The combined renal and bladder sequelae place these children at risk for end stage renal disease and the social stigma of constant urinary wetting. Before the advent of clean intermittent catheterization popularized by Diokno and Lapides,6 and the consistent use of anticholinergics patients experienced continuous urinary incontinence and/or retention, and many required urinary diversion. After the introduction of intermittent catheterization enterocystoplasty became a useful adjunct to improve bladder compliance and preserve renal function. More recently investigators noted that early aggressive nonsurgical management may protect renal function and perhaps prevent the need for augmentation cystoplasty.7–9 However, to
1716
Vol. 176, 1716-1720, October 2006 Printed in U.S.A. DOI:10.1016/S0022-5347(06)00615-X
AUGMENTATION CYSTOPLASTY AT CHILDREN’S HOSPITALS IN UNITED STATES our knowledge no large series in the literature has clearly shown that augmentation cystoplasty rates have decreased in the face of comprehensive nonsurgical management. Collaborative studies have sought to increase research study power and determine clinical practice pattern standards but these studies present logistical hurdles, especially in complex patient populations such as those with myelodysplasia. Prompted by shrinking health care resources and an increasing desire to improve medical care by offering practice standards a number of patient care databases have been created by various health care organizations. The PHIS database was created to allow enrolled hospitals a means of assessing their practices as they relate to other institutions. The database has been used to demonstrate practice pattern variability in treatment for appendicitis, bronchiolitis and asthma, and quantify the impact of adult care performed at pediatric institutions.10 –14 We used the database to analyze augmentation cystoplasty practices across the country in patients with spina bifida. MATERIALS AND METHODS The PHIS Database Data in this study were extracted from the PHIS database, which was created by a business alliance of noncompeting, freestanding children’s hospitals in the United States. The first institution began submitting data in 1992. Since then, 35 medical centers have pooled data, submitting 125 data elements on each patient encountered. The data have been collated on several categories of patient visits, including inpatient admissions, medical short stays, ambulatory surgery visits and emergency department visits, allowing a comparative tool to promote improved medical care and resource use. Of the 20 major metropolitan areas in the United States 17 are represented in this data base. The National Association of Children’s Hospitals and Related Institutions estimated that there are 50 to 55 freestanding pediatric general acute care hospitals in the United States. Of these hospitals 70% submit data to PHIS.10 More than 20,000 physicians providing for more than 250,000 pediatric admissions yearly yield comprehensive data from which outcomes analysis and resource management can be studied. Data include demographics, clinical conditions, payer and cost data, treating physicians and severity indexes using the grouping technology All-Patient Refined Diagnosis Related Groups. Data are submitted electronically to a warehouse in Ann Arbor, Michigan administered by a health care business intelligence company.15 Online data encompass a rolling 5-year period and they are updated every calendar quarter. After a new quarter is added the first quarter is archived with the rest of the data, which date back to 1992. Database Interrogation After institutional review board approval was granted we extracted data on all 0 to 19-year-old patients encountered as inpatient visits between October 1, 1999 and September 30, 2004 with the International Classification of Diseases-9 diagnosis codes for spina bifida (741.9 and 741.0).16 Results were blinded as to the identity of the hospitals, which is consistent with the policies of PHIS and the health care business intelligence company. After the patient pool was created we cross-referenced these patients with the Interna-
1717
tional Classification of Diseases-9 procedure code for augmentation cystoplasty (57.87). Statistical analysis was performed using Student’s paired t test and significance was considered at p ⬍0.05. RESULTS Inpatient data were submitted from 35 children’s medical centers during the study period, accounting for 9,059 hospital beds and servicing an aggregate metropolitan population of 82 million individuals. During the 5-year period 12,925 unique spina bifida patient encounters were identified, including 665 patients who underwent augmentation cystoplasty. Because hospital enrollment is rolling, complete data for analysis were submitted from only 33 institutions during the 4-year period of 2000 to 2003. This represented 9,861 spina bifida patient encounters and 534 augmentation cystoplasties. The male-to-female ratio in children with augmentation was 1:1.2. Median LOS in children with augmentation was 7 days (mean 9). Median preoperative LOS was 1 day. There was no statistically significant difference between the sexes for LOS (p ⫽ 0.51). Median age at augmentation was 10.4 years, that is 11.3 years in boys and 9.8 years in girls. The difference in mean age was statistically significant (p ⬍0.003). At medical centers with pediatric urology fellowships there was an average of 30 augmentation cystoplasties per 5 years in children with spina bifida, while the average number per 5 years at nonfellowship institutions was 14. LOS at fellowship and nonfellowship centers was not statistically different (9.7 vs 8.4 days, p ⫽ 0.24) Likewise the severity index (a weighted factor that considers the number of diagnoses attached to a particular patient) in patients at augmentation was not statistically different between fellowship and nonfellowship programs (p ⫽ 0.5). At institutions where 10 or more augmentations (mean 27) were performed in 5 years mean patient age at operation was 10.1 years. This was significantly younger than at hospitals where fewer than 10 augmentations (mean of 5) were performed in 5 years, that is 12.3 years (p ⬍0.05). LOS at these centers was not statistically different at a mean of 9 days at hospitals with 10 or greater augmentations per 5 years compared to 8.5 days at those with less than 10 augmentations per 5 years (p ⫽ 0.54). Between 2000 and 2003 the rate of augmentation cystoplasty remained the same with a total mean multi-institutional rate of 5.4%, that is 5.3%, 5.5%, 5.4% and 5.4% for each year, respectively (fig. 1). Data also showed tremendous individual institutional variability in the number of patients with spina bifida encountered and in the rate of augmentation cystoplasty in these patients. The difference between the highest and the lowest mean 4-year individual institutional augmentation rate was statistically significant (0.5% to 16.3%, p ⬍0.0001, figs. 2 and 3). There appeared to be little correlation in whether cystoplasty was performed at a higher or lower rate at centers where more children with spina bifida were encountered. DISCUSSION Greater than 90% of patients with spinal dysraphisms have lower urinary tract dysfunction.1 Although the incidence of spinal dysraphisms has decreased due to increased aware-
1718
AUGMENTATION CYSTOPLASTY AT CHILDREN’S HOSPITALS IN UNITED STATES
FIG. 1. Average multi-institutional yearly augmentation rate in children with spina bifida.
ness of the importance of folic acid in neural tube development and the increase in pregnancy termination, the severity of urological disease in the population has remained the same. In the last decade several clinical studies have suggested that aggressive early nonoperative intervention may help protect children and lessen the need for augmentation cystoplasty. Kaefer et al noted a decrease in the need for augmentation in patients treated with early intermittent catheterization and anticholinergic therapy compared to that in observed historical controls with similar urodynamics profiles.7 However, there is controversy regarding the initiation of these measures and whether early or late management has any impact on the ultimate need for bladder augmentation.7,17 In addition, data on long-term sequelae in patients with enteric augmentations to the urinary tract demonstrate that considerable morbidity is associated with this practice.18,19 However, these results stem from small, single institutional studies and little is known about actual trends in management and practice pattern variability. The lack of available data in the literature assessing long-term outcomes in patients with spina bifida has not allowed clarity. More stringent and reproducible clinical and urodynamic criteria are required to determine whether some children
FIG. 2. Number of augmentation cystoplasties in children with spina bifida vs number of unique spina bifida inpatient visits at given institution from 2000 to 2003.
FIG. 3. Augmentation cystoplasty rate per institution from 2000 to 2003.
may be better served by nonsurgical management. Although some experts have suggested that we can manage these cases by a lower rate of bladder augmentation, we could not detect a decreasing trend of augmentation on a large, multiinstitutional level. We noted that the rate of augmentation cystoplasty remained the same during the study period. Expanding the analysis for an extended period may help clarify longer term patterns. We noted a trend toward a greater number of augmentations performed at fellowship training centers. This may be explained by the academic and tertiary nature of the program. However, significant variation exists even between academic medical center practices throughout the country. We could not observe any significant difference of patient severity between nonfellowship and fellowship centers. Also, children underwent augmentation at an earlier age at higher volume centers. Several explanations may be possible for this trend. Perhaps clinician experience allows earlier recognition of the need for augmentation. Conversely this could be explained by the ability of staff at institutions with multidisciplinary spina bifida clinics to maintain more frequent patient followup and act sooner on changes in voiding dysfunction and renal deterioration. A higher rate of augmentation could reflect a lack of urological input until it is too late or a volume of patients overwhelms the available resources. We also noted a difference in age at augmentation between girls and boys. This may be explained by social influences and the degree of maturity. At the preadolescent age girls mature cognitively more rapidly than boys and they may be capable of understanding the logistics of intermittent catheterization, augmentation irrigation and maintenance, while also being more socially aware of incontinence at an earlier age. Patients confined to a wheelchair may find it to be technically more difficult to catheterize through the female urethra, prompting a demand from patients and caregivers to intervene sooner. Also, girls achieve menarche near the time of the median augmentation age of 9.8 years and it may be easier to catheterize through an abdominal stoma after menstruation cycles occur.
AUGMENTATION CYSTOPLASTY AT CHILDREN’S HOSPITALS IN UNITED STATES The use of multi-institutional databases to assess outcomes enables observers to make conclusions based on high powered data, while minimizing the degree of influence from statistical noise. Newman11 and Ponsky10 et al used PHIS to analyze practice pattern variability in the treatment of appendicitis by analyzing data from 30 hospitals evaluating 3,393 children. They determined positive and nonpositive operative and nonoperative rates, described the financial charge per patient, assessed rehospitalization rates and looked at the use of laparoscopy, antibiotics, anti-emetics and various imaging modalities. They concluded that there was significant practice pattern variability and no best practices existed to guide clinicians to provide highly successful and efficient care. They suggested that future multi-institutional collaboration might allow a quality initiative to share and adopt improved practice patterns for antibiotic, anti-emetic and analgesic regimens. Goodman et al used the PHIS database to describe the impact that adult patients have on children’s medical centers. They noted that among 6 institutions 3,863 patients 18 to 64 years old incurred $134.5 million of charges during a total of 5,051 hospital encounters between 1994 and 1999. This demonstrated how powerful a tool PHIS was at describing a specific patient population. From these data they were able to identify the 3 most common diagnoses in these adults, that is cystic fibrosis, mental retardation or cerebral palsy and congenital heart disease. They concluded that perhaps a new subspecialty geared specifically at adult patients at childhood diseases should be created to assume care of these unique patients.14 Use of the PHIS database to assess outcomes analysis contains inherent weaknesses. For example, the database relies on proper coding from each institution and it may be influenced by variability in coding practices among physicians and coders alike. In addition, there is selection bias, in that some institutions enrolled in PHIS may be tertiary referral centers, while others may function as community hospitals servicing the local region, and there may be sampling bias, in that PHIS does not track all hospitals, so that the database is not a population survey. Also, some institutions are academic and affiliated with universities, and have residency and fellowship training responsibilities, and by their nature medicine may be practiced differently there than at private, nonacademic centers. In addition, geographic and regional variations may have a role in selection bias, yielding the disparate patient demographics encountered. Future studies exploiting multiple databases will enable us to study disease as more of a population or census based study as we are able to capture the majority of children in the United States. A cohort study following children from birth through childhood may aid in determining the overall risk of requiring augmentation cystoplasty and case-control studies may define a difference in augmentation risk by era in matched nonoperated controls. Likewise identifying peer hospitals that share similar profiles with regard to size, referral patterns, managed care markets and academic pursuits will enable us to define centers specializing in specific patient diseases and create a benchmark from which other institutions may practice.
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CONCLUSIONS There is significant practice pattern variability in managing the urinary tract of children with spina bifida. We did not identify a trend toward decreasing surgical intervention and there does not appear to be a trend toward surgical intervention at centers that see more children with spina bifida. It remains to be seen if more aggressive nonoperative management of patients with spina bifida translates into decreasing bladder augmentation rates. Expanding the analysis to multiple databases and tracking patients in a prospective manner will allow us to develop practice standards to ensure optimal patient care. ACKNOWLEDGMENTS The PHIS database was created at Child Health Corp., Shawnee Mission, Kansas. Data are submitted electronically to Solucient LLC, Evanston, Illinois.
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