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Regional variation in rates of pediatric perforated appendicitis
Journal of Pediatric Surgery 52 (2017) 1488–1491
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Regional variation in rates of pediatric perforated appendicitis Samir Sarda a, Heather L. Short b, Jason M. Hockenberry a, Ian McCarthy c, Mehul V. Raval b,⁎ a b c
Department of Health Policy and Management, Rollins School of Public Health, Emory University, Atlanta, GA, USA Division of Pediatric Surgery, Department of Surgery, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, USA Deparment of Economics, Emory University, Atlanta, GA, USA
a r t i c l e
i n f o
Article history: Received 13 September 2016 Received in revised form 9 February 2017 Accepted 11 February 2017 Key words: Perforated appendicitis Pediatric surgery Pediatric quality indicators Health outcomes Kids' Inpatient Database (KID)
a b s t r a c t Background: While trends in perforated appendicitis (PA) rates have been studied, regional variability in pediatric admissions for PA remains unknown. Methods: A retrospective, cross-sectional analysis of the 2006–2012 Kids' Inpatient Database was conducted to examine variation in PA admission rates by region of the United States and insurance status. PA rates were calculated and reported as per 1000 admissions in accordance with national quality measure specifications. Results: National PA rates per 1000 admissions for 2006, 2009, and 2012 were 313.9, 279.2, and 309.1, respectively. Similarly, all regions demonstrated a statistically significant decrease in PA rates between 2006 and 2009 (p b 0.001), where the increase in rates between 2009 and 2012 was only statistically significant in the Midwest [Odds Ratio (OR) 1.07; 95% Confidence Interval (95%CI) 1.03–1.12] and West (OR 1.10; 95% CI 1.07–1.14). The Northeast consistently experienced the lowest PA rates. The odds of PA were highest among uninsured patients (OR 1.35; 95% CI 1.31–1.29). The South had the highest proportion of uninsured children, and these patients had the highest odds of perforation (OR 1.57; 95% CI 1.21–2.02). Conclusions: For children with appendicitis, geographic region and insurance status appear to be associated with perforation upon presentation. Understanding regional variation in pediatric PA rates may inform health policymakers in the constantly evolving insurance coverage landscape. Levels of evidence rating: Level III Treatment Study — Retrospective comparative study of appendicitis presentation in children by region of the country. © 2017 Elsevier Inc. All rights reserved.
With the passage of the Affordable Care Act (ACA) in 2010, national health care policies have begun to focus on prevention and incentivizing the provision of coordinated value-based care. By establishing the Prevention and Public Health Fund [1], mandating health plans to cover certain preventive benefits free of cost-sharing [2,3] and enabling young adults to remain on the insurance plans of their parents until twenty-six years of age through the Dependent Coverage Provision (DCP) [4,5], efforts to expand access to care have become a vital prevention strategy. Nonetheless, initiatives to identify and track disparities in accessing care among various adult and pediatric populations had already been underway. In 2001, the Agency for Healthcare Research and Quality (AHRQ) developed a list of prevention quality indicators (PQIs) to drive improvements in quality metrics such as admissions for ambulatory care sensitive conditions [6]. Given the ability of both patients and providers in outpatient settings to prevent certain complica-
Abbreviations: AHRQ, Agency for Healthcare Research and Quality; PQI, prevention quality indicator; PDI, pediatric quality indicator; KID, Kids' Inpatient Database. ⁎ Corresponding author at: Division of Pediatric Surgery, Department of Surgery, Emory University School of Medicine, Children's Healthcare of Atlanta, 1405 Clifton Road NE, Atlanta, GA 30322. Tel.: +1 404 785 0781; fax: +1 404 785 0800. E-mail address: [email protected] (M.V. Raval). http://dx.doi.org/10.1016/j.jpedsurg.2017.02.009 0022-3468/© 2017 Elsevier Inc. All rights reserved.
tions and minimize the severity of disease, the AHRQ, in 2006, devised a list of 24 hospital- and area-level pediatric quality indicators (PDIs), including perforated appendix admission rate as PDI-17 [7]. Improvements in access to timely surgical evaluations, patient education on the symptoms of appendicitis, and the number of misdiagnoses have all been cited as interventions that could substantially decrease the frequency of perforated appendix cases [6,8,9]. While much of the current literature on appendicitis care has centered on the effectiveness of various treatment options, such as comparisons between laparoscopic and open appendectomies [10–12], few studies have examined the preliminary effects of the post-ACA health care environment on admission rates for perforated appendices. The purpose of this study was to assess both regional variation in and the effect of insurance status on pediatric perforated appendix admission rates. We hypothesized that the passage of the ACA would result in a lower proportion of uninsured patients and therefore lower perforated appendicitis rates. Providing clinicians and health policy experts with an understanding of how region-specific rates have varied between 2006 and 2012 and whether they are associated with insurance status is imperative to later determining the effect of national policies, such as Medicaid expansion, on rates of pediatric admissions for perforated appendices.
S. Sarda et al. / Journal of Pediatric Surgery 52 (2017) 1488–1491
1. Methods 1.1. Study design A retrospective, cross-sectional analysis of the three most recent releases (2006, 2009 and 2012) of the Kids' Inpatient Database (KID) was performed to study the variation in perforated appendix admission rates by region of the United States. The KID, which was developed by the Agency of Healthcare Research and Quality (AHRQ) for the Healthcare Cost and Utilization Project (HCUP), is a national database of administrative, billing, and hospital discharge-level data for all patients less than the age of 21 [13]. The approximately 3 million pediatric discharge records per year stored in the KID are sampled from all community, nonrehabilitation hospitals of those states participating in HCUP. In 2012, that included a regionally diverse mix of 44 states, up from 27 states in the 2000 KID [13]. The increasing number of states represented in the KID's sampling frame has led to greater coverage of the national inpatient discharge population over time. National estimates of discharges were generated using the discharge weights provided by HCUP [13–15]. These weights are determined based on poststratification of hospitals according to ownership status, bed size, teaching status, rural/urban classification, region of the U.S., and the designation as a freestanding children's hospital. Records from each hospital are randomly sampled to include 10% of uncomplicated births and 80% of complicated births alongside other pediatric cases [13]. Fewer uncomplicated births are sampled because less variation in outcomes is expected for this lower-risk population. Each discharge record in the KID is populated with more than 100 clinical and nonclinical data elements, ranging from patient demographics to hospital charges and diagnosis and procedure codes. The Children's Healthcare of Atlanta Institutional Review Board deemed this study to be exempt from ethical review owing to the deidentified nature of the KID. 1.2. Data analysis Admission rates for perforated appendicitis were calculated and reported as per 1000 admissions in accordance with AHRQ specifications given the metric's designation as a pediatric quality indicator [15]. Specifically, discharges for patients between 1 and 17 years of age with International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) diagnosis codes for acute appendicitis with peritonitis (540.0) or an abscess of appendix (540.1) were included in the numerator. Obstetric admissions and transfers from outside facilities were excluded. All ICD-9-CM diagnosis codes for appendicitis in patients between 1 and 17 years old were included in the denominator (540.0, 540.1, 540.9, 541) [15]. Sample weights were used to generate national estimates of perforated appendix discharges prior to calculating perforated appendix rates per 1000 admissions. For trend analyses, discharge records with missing procedure data were excluded. National rates for each KID year studied as well as region-specific perforated appendix admission rates were determined. To identify discharge- and hospital-level risk factors for perforated appendicitis, univariable followed by multivariable logistic regression analyses were performed using the following covariates: sex, race/ethnicity (White vs. Nonwhite), insurance status (uninsured vs. insured), hospital type (children's hospital vs. nonchildren's hospital), county classification (rural/micropolitan vs. urban/metropolitan), and median household income by zip code (high vs. low). For the purposes of this study, discharges coded as ‘uninsured’ were those classified as either self-pay or no charge while ‘insured’ signified inpatient visits covered by either Medicare, Medicaid, private or other insurance. County classification was grouped into ‘rural/micropolitan’ if neither micropolitan nor metropolitan designations were given or if the patients' residential counties were between 10,000 and 50,000 in size. ‘Urban/metropolitan’ status was defined as those patients living in counties with populations greater than 50,000. Patients residing in zip codes with median
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household incomes in the top two quartiles were considered to be living in a ‘high-income area’ and those in the two lowest quartiles were recognized as living in a ‘low-income area’ [5,13]. Binary logistic regression was also conducted to assess trends in perforated appendix admission rates between 2006 and 2012 and to compare such rates across years by region of the U.S. Since overall insurance coverage was greatest in the Northeast in 2012, the Northeast was chosen as the reference region. All statistical models were generated using IBM SPSS Statistics Version 23 in order to account for the KID's complex survey design. As with multiyear trend analyses and standard error calculations, all rates and discharge-level data that were scaled to acquire national weighted estimates were generated according to HCUP's validated approach [13,15]. Statistical significance was defined as p ≤ 0.05 when interpreting the results of all regression analyses. 2. Results 2.1. Perforated appendix rates National perforated appendix rates per 1000 admissions were 313.9 in 2006, 279.2 in 2009, and 309.1 in 2012. All regions experienced statistically significant declines in perforated appendix rates between 2006 and 2009, but the increase in rates between 2009 and 2012 was only significant in the Midwest (Odds Ratio (OR) 1.07, 95% Confidence Interval (CI) 1.03–1.12, p b 0.001) and West (OR 1.10, 95% CI 1.07–1.14, p b 0.001) (Fig. 1). While the perforated appendix rate in the Midwest was lower than the West and the South in 2006, it was highest in both 2009 and 2012, reaching 363.7 per 1000 pediatric admissions. The variations in all other regions were less dramatic and resulted in net declines in perforated appendix rates between 2006 and 2012. Relative to the Northeast, which has consistently exhibited the lowest perforated appendix admission rates, the Midwest saw significantly higher rates in 2012 while the West has experienced significantly higher rates in all three of the years studied (p b 0.001). 2.2. Insurance coverage In the cumulative study period among all pediatric admissions, the South was responsible for the largest proportion of uninsured (5.3%) and publicly insured admissions (56.4%). The percent of pediatric patients who were uninsured in the region dropped from 6.8% to 4.7% after a 19.1% decline from 2006 to 2009 and a 13.6% decline from 2009 to 2012 (Fig. 2). During those two, three-year intervals, uninsured rates among hospitalized children dropped in the Midwest (−9.6% and −12.7%, respectively) and the Northeast (−20.6% and −41.7%, respectively) as well. However, a 15.1% increase to 4.0% uninsured was found in the West between 2009 and 2012. Though the proportion of all admissions covered by private insurance was greatest in the Northeast, the percentage of perforated appendix admissions covered by private insurance was largest in the Midwest (59.0%). Of those who presented with perforated appendicitis, as many as 6.6% were uninsured (South) and as many as 51.0% were publicly insured (West). 2.3. Risk factors associated with perforated appendix Multivariable logistic regression analysis across the study period identified being male (p b 0.001) and nonwhite (p b 0.001) as significant predictors of being treated for a perforated appendix (Table 1). Moreover, the results suggest that patients with perforated appendicitis have more than 3 times the odds of being treated at a children's hospital than a nonchildren's hospital. On a national level, children and adolescents are more likely to present with perforated appendicitis if they are uninsured (OR 1.35, CI 1.31–1.39, p b 0.001). Region-specific models suggested that in the South uninsured patients have increased odds of presenting with a perforated appendix (OR 1.57, 95% CI 1.21–2.02, p b 0.001). Insurance status was not significantly associated with
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S. Sarda et al. / Journal of Pediatric Surgery 52 (2017) 1488–1491
Fig. 1. National and regional trends in perforated appendix admission rates among children between 2006 and 2012.
perforated appendix rates in any other region of the U.S., and no differences in public versus private insurance within or across regions were observed. 3. Discussion To our knowledge, this is the first pediatric study to simultaneously examine the effect of insurance status on perforated appendix admission rates by region of the U.S. National and regional rates of this pediatric quality indicator showed decreasing followed by increasing trends between 2006 and 2012, with the Midwest moving from having the second-lowest perforated appendix rate to the highest in 2012. The largest proportion of uninsured children, however, was found in the South for all three years studied, and patients with insurance in that region were significantly less likely to present with a perforated appendix compared to uninsured patients. The Northeast consistently had the lowest proportion of perforated appendicitis admissions. Although additional supporting literature is lacking, the finding that geographic region and insurance status are associated with perforated appendicitis rates may have important implications regarding measures to prevent delayed presentation of appendicitis in children. Given the vast social, cultural, and political differences that exist throughout the U.S., our
results call for further research into how the adoption of various health care policies, such as Medicaid expansion, by region and by state affect rates of perforated appendicitis in children. Previous studies have cited various demographic and communitylevel factors to explain variations in perforated appendix rates over time, such as travel time, insurance status, and residing in a health professional shortage area [8,16–19]. Racial and economic disparities in perforated appendicitis rates have been examined as well, with multiple references to differences specifically in care-seeking behavior, financial hardship, and the receipt of high-quality care as contributing factors [19,20]. Our findings in this regional analysis that males, minorities, and uninsured children all face higher odds of being treated for perforated appendicitis align with what has been previously reported in both national and state-specific pediatric studies [16,21]. However, higher perforation rates were not observed among those covered by public insurance compared to private insurance either nationally or for a given region. Fewer delays in seeking and accessing care given their coverage as well as growth in the proportion of publicly insured in 2009, following the recession, and in 2012, post-ACA, may be partially responsible for this result. While the 2012 spike in perforated appendix rates in the West may be explained by the 15% increase in the uninsured since 2009, reasons for the more dramatic increase found in the
Fig. 2. Regional trends in percentage of uninsured patients among all pediatric admissions between 2006 and 2012.
S. Sarda et al. / Journal of Pediatric Surgery 52 (2017) 1488–1491 Table 1 Multivariable analysis of demographic and hospital-level risk factors associated with perforated appendicitis. Risk Factors
OR (95% CI)
p-value
Female Nonwhite Children's Hospitals Urban/Metropolitan High Income Area Uninsured
0.62 (0.61–0.63) 1.16 (1.15–1.18) 3.62 (3.56–3.68) 1.00 (0.98–1.03) 1.04 (1.02–1.05) 1.35 (1.31–1.39)
b0.001 b0.001 b0.001 0.803 b0.001 b0.001
OR = Odds ratio; CI = Confidence interval.
Midwest remain unknown and call for further investigation. Follow-up studies comparing perforated appendix admission rates among children by region and state with data that capture the effects of the implementation of Medicaid expansion in 2014 are highly warranted. Several limitations must be considered when interpreting the results of this study. For one, the number of states who participated in HCUP and contributed data to the KID increased from 38 in 2006 to 44 in 2009 and 2012 [13], resulting in changes to the KID's sampling frame over the study period. Consequently, accurately comparing regional estimates of perforated appendix admission rates and insurance coverage remains difficult. In addition, multivariable logistic regression analyses used the Northeast as the reference region to assess trends in perforated appendix admission rates even though overall insurance coverage was greatest in the West in 2006 and 2009. However, the region more accurately depicted regional trends relative to one another owing to its consistency in having the lowest pediatric perforated appendix rates. Lastly, this cross-sectional analysis fails to recognize the role of underinsurance, which applies to individuals who has insurance, but does not have the financial means to cover the out-of-pocket expenses associated with healthcare. This is an important consideration when making comparisons of access-related metrics between insured and uninsured children given the prevalence of cost sharing features that accompany public and private insurance plans.
4. Conclusion For children with appendicitis, both geographic region and insurance status appear to be associated with perforation upon presentation. Further investigation is needed to better understand the regional variation in perforated appendicitis rates among children and the role of insurance status on such rates. These insights will inform health policymakers as initiatives within the Affordable Care Act, such as Medicaid expansion, as well as other national and state-level policies continue to evolve.
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Acknowledgments MVR was supported by the Pediatric Research Alliance of Emory University and Children's Healthcare of Atlanta as well as by the Department of Surgery at Emory University School of Medicine. References [1] Mays GP, Smith SA. Evidence links increases in public health spending to declines in preventable deaths. Health Aff 2011;30(8):1585–93. [2] Maciosek MV, Coffield AB, Flottemesch TJ, et al. Greater use of preventive services in U.S. health care could save lives at little or no cost. Health Aff 2010;29(9):1656–60. [3] Rosenbaum S. The patient protection and affordable care act: implications for public health policy and practice. Public Health Rep 2011;126(1):130–5. [4] French MT, Homer J, Gumus G, et al. Key provisions of the patient protection and Affordable Care Act (ACA): a systematic review and presentation of early research findings. Health Serv Res 2016. http://dx.doi.org/10.1111/1475-6773.12511 [Epub ahead of print]. [5] Scott JW, Rose JA, Tsai TC, et al. Impact of ACA insurance coverage expansion on perforated appendix rates among young adults. Med Care 2016;54(9):818–26. [6] Agency for Healthcare Research and Quality (AHRQ) quality indicators—guide to prevention quality indicators: hospital admission for ambulatory care sensitive conditions. Rockville, MD: Agency for Healthcare Research and Quality; 2001[AHRQ Pub. No 02-R0203]. [7] Agency for Healthcare Research and Quality (AHRQ) quality indicators: pediatric quality indicators. Rockville, MD: Agency for Healthcare Research and Quality; 2015[AHRQ Pub. No. 15-M053–2-EF]. [8] Drake FT, Mottey NE, Farrokhi ET, et al. Time to appendectomy and risk of perforation in acute appendicitis. JAMA Surg 2014;149:837–44. [9] Jablonski KA, Guagliardo MF. Pediatric appendicitis rupture rate: a national indicator of disparities in healthcare access. Popul Health Metr 2005;3:4. [10] Masoomi H, Nguyen NT, Dolich MO, et al. Laparoscopic appendectomy trends and outcomes in the United States: data from the Nationwide Inpatient Sample (NIS), 2004–2011. Am Surg 2014;80(10):1074–7. [11] Cheong LH, Emil S. Pediatric laparoscopic appendectomy: a population-based study of trends, associations, and outcomes. J Pediatr Surg 2014;49(12):1714–8. [12] Sleem R, Fisher S, Gestring M, et al. Perforated appendicitis: is early laparoscopic appendectomy appropriate? Surgery 2009;146(4):731–7. [13] Introduction to the HCUP KIDs' Inpatient Database (KID). Healthcare Cost and Utilization Project (HCUP). Rockville, MD: Agency for Healthcare Research and Quality; 2012 [https://www.hcup-us.ahrq.gov/db/nation/kid/KID_2012_Introduction.pdf]. [14] McDonald KM, Davies SM, Haberland CA, et al. Preliminary assessment of pediatric health care quality and patient safety in the United States using readily available administrative data. Pediatrics 2008;122(2):e416–25. http://dx.doi.org/10.1542/peds. 2007-2477. [15] Agency for Healthcare Research and Quality. Pediatric quality indicators #17: technical specifications. Rockville, MD: Agency for Healthcare Research and Quality (AHRQ): Perforated appendix admission rate [version 5.0]; 2015 [http://www. qualityindicators.ahrq.gov/Downloads/Modules/PDI/V50/TechSpecs/PDI_17_Perforated_Appendix_Admission_Rate.pdf]. [16] Ponsky TA, Huang ZJ, Kittle K, et al. Hospital- and patient-level characteristics and the risk of appendiceal rupture and negative appendectomy in children. JAMA 2004;292:1977–82. [17] O'Toole SJ, Karamanoukian HL, Allen JE. Insurance-related differences in the presentation of pediatric appendicitis. J Pediatr Surg 1996;31:1032–4. [18] Paquette IM, Zuckerman R, Finlayson SRG. Perforated appendicitis among rural and urban patients: implications of access to care. Ann Surg 2011;253:534–8. [19] Neuwahl S, Ricketts T, Holmes M. The impact of general surgeon supply on the risk of appendiceal rupture in North Carolina. Ann Surg 2014;259:910–5. [20] Pieracci FM, Eachempati SR, Barie PS, et al. Insurance status, but not race, predicts perforation in adult patients with acute appendicitis. J Am Coll Surg 2007;205:445–52. [21] Jablonski KA, Guagliardo MF. Pediatric appendicitis rupture rate: a national indicator of disparities in healthcare access. Popul Health Metr 2005;3:1–9.
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Regional variation in rates of pediatric perforated appendicitis Samir Sarda a, Heather L. Short b, Jason M. Hockenberry a, Ian McCarthy c, Mehul V. Raval b,⁎ a b c
Department of Health Policy and Management, Rollins School of Public Health, Emory University, Atlanta, GA, USA Division of Pediatric Surgery, Department of Surgery, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, USA Deparment of Economics, Emory University, Atlanta, GA, USA
a r t i c l e
i n f o
Article history: Received 13 September 2016 Received in revised form 9 February 2017 Accepted 11 February 2017 Key words: Perforated appendicitis Pediatric surgery Pediatric quality indicators Health outcomes Kids' Inpatient Database (KID)
a b s t r a c t Background: While trends in perforated appendicitis (PA) rates have been studied, regional variability in pediatric admissions for PA remains unknown. Methods: A retrospective, cross-sectional analysis of the 2006–2012 Kids' Inpatient Database was conducted to examine variation in PA admission rates by region of the United States and insurance status. PA rates were calculated and reported as per 1000 admissions in accordance with national quality measure specifications. Results: National PA rates per 1000 admissions for 2006, 2009, and 2012 were 313.9, 279.2, and 309.1, respectively. Similarly, all regions demonstrated a statistically significant decrease in PA rates between 2006 and 2009 (p b 0.001), where the increase in rates between 2009 and 2012 was only statistically significant in the Midwest [Odds Ratio (OR) 1.07; 95% Confidence Interval (95%CI) 1.03–1.12] and West (OR 1.10; 95% CI 1.07–1.14). The Northeast consistently experienced the lowest PA rates. The odds of PA were highest among uninsured patients (OR 1.35; 95% CI 1.31–1.29). The South had the highest proportion of uninsured children, and these patients had the highest odds of perforation (OR 1.57; 95% CI 1.21–2.02). Conclusions: For children with appendicitis, geographic region and insurance status appear to be associated with perforation upon presentation. Understanding regional variation in pediatric PA rates may inform health policymakers in the constantly evolving insurance coverage landscape. Levels of evidence rating: Level III Treatment Study — Retrospective comparative study of appendicitis presentation in children by region of the country. © 2017 Elsevier Inc. All rights reserved.
With the passage of the Affordable Care Act (ACA) in 2010, national health care policies have begun to focus on prevention and incentivizing the provision of coordinated value-based care. By establishing the Prevention and Public Health Fund [1], mandating health plans to cover certain preventive benefits free of cost-sharing [2,3] and enabling young adults to remain on the insurance plans of their parents until twenty-six years of age through the Dependent Coverage Provision (DCP) [4,5], efforts to expand access to care have become a vital prevention strategy. Nonetheless, initiatives to identify and track disparities in accessing care among various adult and pediatric populations had already been underway. In 2001, the Agency for Healthcare Research and Quality (AHRQ) developed a list of prevention quality indicators (PQIs) to drive improvements in quality metrics such as admissions for ambulatory care sensitive conditions [6]. Given the ability of both patients and providers in outpatient settings to prevent certain complica-
Abbreviations: AHRQ, Agency for Healthcare Research and Quality; PQI, prevention quality indicator; PDI, pediatric quality indicator; KID, Kids' Inpatient Database. ⁎ Corresponding author at: Division of Pediatric Surgery, Department of Surgery, Emory University School of Medicine, Children's Healthcare of Atlanta, 1405 Clifton Road NE, Atlanta, GA 30322. Tel.: +1 404 785 0781; fax: +1 404 785 0800. E-mail address: [email protected] (M.V. Raval). http://dx.doi.org/10.1016/j.jpedsurg.2017.02.009 0022-3468/© 2017 Elsevier Inc. All rights reserved.
tions and minimize the severity of disease, the AHRQ, in 2006, devised a list of 24 hospital- and area-level pediatric quality indicators (PDIs), including perforated appendix admission rate as PDI-17 [7]. Improvements in access to timely surgical evaluations, patient education on the symptoms of appendicitis, and the number of misdiagnoses have all been cited as interventions that could substantially decrease the frequency of perforated appendix cases [6,8,9]. While much of the current literature on appendicitis care has centered on the effectiveness of various treatment options, such as comparisons between laparoscopic and open appendectomies [10–12], few studies have examined the preliminary effects of the post-ACA health care environment on admission rates for perforated appendices. The purpose of this study was to assess both regional variation in and the effect of insurance status on pediatric perforated appendix admission rates. We hypothesized that the passage of the ACA would result in a lower proportion of uninsured patients and therefore lower perforated appendicitis rates. Providing clinicians and health policy experts with an understanding of how region-specific rates have varied between 2006 and 2012 and whether they are associated with insurance status is imperative to later determining the effect of national policies, such as Medicaid expansion, on rates of pediatric admissions for perforated appendices.
S. Sarda et al. / Journal of Pediatric Surgery 52 (2017) 1488–1491
1. Methods 1.1. Study design A retrospective, cross-sectional analysis of the three most recent releases (2006, 2009 and 2012) of the Kids' Inpatient Database (KID) was performed to study the variation in perforated appendix admission rates by region of the United States. The KID, which was developed by the Agency of Healthcare Research and Quality (AHRQ) for the Healthcare Cost and Utilization Project (HCUP), is a national database of administrative, billing, and hospital discharge-level data for all patients less than the age of 21 [13]. The approximately 3 million pediatric discharge records per year stored in the KID are sampled from all community, nonrehabilitation hospitals of those states participating in HCUP. In 2012, that included a regionally diverse mix of 44 states, up from 27 states in the 2000 KID [13]. The increasing number of states represented in the KID's sampling frame has led to greater coverage of the national inpatient discharge population over time. National estimates of discharges were generated using the discharge weights provided by HCUP [13–15]. These weights are determined based on poststratification of hospitals according to ownership status, bed size, teaching status, rural/urban classification, region of the U.S., and the designation as a freestanding children's hospital. Records from each hospital are randomly sampled to include 10% of uncomplicated births and 80% of complicated births alongside other pediatric cases [13]. Fewer uncomplicated births are sampled because less variation in outcomes is expected for this lower-risk population. Each discharge record in the KID is populated with more than 100 clinical and nonclinical data elements, ranging from patient demographics to hospital charges and diagnosis and procedure codes. The Children's Healthcare of Atlanta Institutional Review Board deemed this study to be exempt from ethical review owing to the deidentified nature of the KID. 1.2. Data analysis Admission rates for perforated appendicitis were calculated and reported as per 1000 admissions in accordance with AHRQ specifications given the metric's designation as a pediatric quality indicator [15]. Specifically, discharges for patients between 1 and 17 years of age with International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) diagnosis codes for acute appendicitis with peritonitis (540.0) or an abscess of appendix (540.1) were included in the numerator. Obstetric admissions and transfers from outside facilities were excluded. All ICD-9-CM diagnosis codes for appendicitis in patients between 1 and 17 years old were included in the denominator (540.0, 540.1, 540.9, 541) [15]. Sample weights were used to generate national estimates of perforated appendix discharges prior to calculating perforated appendix rates per 1000 admissions. For trend analyses, discharge records with missing procedure data were excluded. National rates for each KID year studied as well as region-specific perforated appendix admission rates were determined. To identify discharge- and hospital-level risk factors for perforated appendicitis, univariable followed by multivariable logistic regression analyses were performed using the following covariates: sex, race/ethnicity (White vs. Nonwhite), insurance status (uninsured vs. insured), hospital type (children's hospital vs. nonchildren's hospital), county classification (rural/micropolitan vs. urban/metropolitan), and median household income by zip code (high vs. low). For the purposes of this study, discharges coded as ‘uninsured’ were those classified as either self-pay or no charge while ‘insured’ signified inpatient visits covered by either Medicare, Medicaid, private or other insurance. County classification was grouped into ‘rural/micropolitan’ if neither micropolitan nor metropolitan designations were given or if the patients' residential counties were between 10,000 and 50,000 in size. ‘Urban/metropolitan’ status was defined as those patients living in counties with populations greater than 50,000. Patients residing in zip codes with median
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household incomes in the top two quartiles were considered to be living in a ‘high-income area’ and those in the two lowest quartiles were recognized as living in a ‘low-income area’ [5,13]. Binary logistic regression was also conducted to assess trends in perforated appendix admission rates between 2006 and 2012 and to compare such rates across years by region of the U.S. Since overall insurance coverage was greatest in the Northeast in 2012, the Northeast was chosen as the reference region. All statistical models were generated using IBM SPSS Statistics Version 23 in order to account for the KID's complex survey design. As with multiyear trend analyses and standard error calculations, all rates and discharge-level data that were scaled to acquire national weighted estimates were generated according to HCUP's validated approach [13,15]. Statistical significance was defined as p ≤ 0.05 when interpreting the results of all regression analyses. 2. Results 2.1. Perforated appendix rates National perforated appendix rates per 1000 admissions were 313.9 in 2006, 279.2 in 2009, and 309.1 in 2012. All regions experienced statistically significant declines in perforated appendix rates between 2006 and 2009, but the increase in rates between 2009 and 2012 was only significant in the Midwest (Odds Ratio (OR) 1.07, 95% Confidence Interval (CI) 1.03–1.12, p b 0.001) and West (OR 1.10, 95% CI 1.07–1.14, p b 0.001) (Fig. 1). While the perforated appendix rate in the Midwest was lower than the West and the South in 2006, it was highest in both 2009 and 2012, reaching 363.7 per 1000 pediatric admissions. The variations in all other regions were less dramatic and resulted in net declines in perforated appendix rates between 2006 and 2012. Relative to the Northeast, which has consistently exhibited the lowest perforated appendix admission rates, the Midwest saw significantly higher rates in 2012 while the West has experienced significantly higher rates in all three of the years studied (p b 0.001). 2.2. Insurance coverage In the cumulative study period among all pediatric admissions, the South was responsible for the largest proportion of uninsured (5.3%) and publicly insured admissions (56.4%). The percent of pediatric patients who were uninsured in the region dropped from 6.8% to 4.7% after a 19.1% decline from 2006 to 2009 and a 13.6% decline from 2009 to 2012 (Fig. 2). During those two, three-year intervals, uninsured rates among hospitalized children dropped in the Midwest (−9.6% and −12.7%, respectively) and the Northeast (−20.6% and −41.7%, respectively) as well. However, a 15.1% increase to 4.0% uninsured was found in the West between 2009 and 2012. Though the proportion of all admissions covered by private insurance was greatest in the Northeast, the percentage of perforated appendix admissions covered by private insurance was largest in the Midwest (59.0%). Of those who presented with perforated appendicitis, as many as 6.6% were uninsured (South) and as many as 51.0% were publicly insured (West). 2.3. Risk factors associated with perforated appendix Multivariable logistic regression analysis across the study period identified being male (p b 0.001) and nonwhite (p b 0.001) as significant predictors of being treated for a perforated appendix (Table 1). Moreover, the results suggest that patients with perforated appendicitis have more than 3 times the odds of being treated at a children's hospital than a nonchildren's hospital. On a national level, children and adolescents are more likely to present with perforated appendicitis if they are uninsured (OR 1.35, CI 1.31–1.39, p b 0.001). Region-specific models suggested that in the South uninsured patients have increased odds of presenting with a perforated appendix (OR 1.57, 95% CI 1.21–2.02, p b 0.001). Insurance status was not significantly associated with
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S. Sarda et al. / Journal of Pediatric Surgery 52 (2017) 1488–1491
Fig. 1. National and regional trends in perforated appendix admission rates among children between 2006 and 2012.
perforated appendix rates in any other region of the U.S., and no differences in public versus private insurance within or across regions were observed. 3. Discussion To our knowledge, this is the first pediatric study to simultaneously examine the effect of insurance status on perforated appendix admission rates by region of the U.S. National and regional rates of this pediatric quality indicator showed decreasing followed by increasing trends between 2006 and 2012, with the Midwest moving from having the second-lowest perforated appendix rate to the highest in 2012. The largest proportion of uninsured children, however, was found in the South for all three years studied, and patients with insurance in that region were significantly less likely to present with a perforated appendix compared to uninsured patients. The Northeast consistently had the lowest proportion of perforated appendicitis admissions. Although additional supporting literature is lacking, the finding that geographic region and insurance status are associated with perforated appendicitis rates may have important implications regarding measures to prevent delayed presentation of appendicitis in children. Given the vast social, cultural, and political differences that exist throughout the U.S., our
results call for further research into how the adoption of various health care policies, such as Medicaid expansion, by region and by state affect rates of perforated appendicitis in children. Previous studies have cited various demographic and communitylevel factors to explain variations in perforated appendix rates over time, such as travel time, insurance status, and residing in a health professional shortage area [8,16–19]. Racial and economic disparities in perforated appendicitis rates have been examined as well, with multiple references to differences specifically in care-seeking behavior, financial hardship, and the receipt of high-quality care as contributing factors [19,20]. Our findings in this regional analysis that males, minorities, and uninsured children all face higher odds of being treated for perforated appendicitis align with what has been previously reported in both national and state-specific pediatric studies [16,21]. However, higher perforation rates were not observed among those covered by public insurance compared to private insurance either nationally or for a given region. Fewer delays in seeking and accessing care given their coverage as well as growth in the proportion of publicly insured in 2009, following the recession, and in 2012, post-ACA, may be partially responsible for this result. While the 2012 spike in perforated appendix rates in the West may be explained by the 15% increase in the uninsured since 2009, reasons for the more dramatic increase found in the
Fig. 2. Regional trends in percentage of uninsured patients among all pediatric admissions between 2006 and 2012.
S. Sarda et al. / Journal of Pediatric Surgery 52 (2017) 1488–1491 Table 1 Multivariable analysis of demographic and hospital-level risk factors associated with perforated appendicitis. Risk Factors
OR (95% CI)
p-value
Female Nonwhite Children's Hospitals Urban/Metropolitan High Income Area Uninsured
0.62 (0.61–0.63) 1.16 (1.15–1.18) 3.62 (3.56–3.68) 1.00 (0.98–1.03) 1.04 (1.02–1.05) 1.35 (1.31–1.39)
b0.001 b0.001 b0.001 0.803 b0.001 b0.001
OR = Odds ratio; CI = Confidence interval.
Midwest remain unknown and call for further investigation. Follow-up studies comparing perforated appendix admission rates among children by region and state with data that capture the effects of the implementation of Medicaid expansion in 2014 are highly warranted. Several limitations must be considered when interpreting the results of this study. For one, the number of states who participated in HCUP and contributed data to the KID increased from 38 in 2006 to 44 in 2009 and 2012 [13], resulting in changes to the KID's sampling frame over the study period. Consequently, accurately comparing regional estimates of perforated appendix admission rates and insurance coverage remains difficult. In addition, multivariable logistic regression analyses used the Northeast as the reference region to assess trends in perforated appendix admission rates even though overall insurance coverage was greatest in the West in 2006 and 2009. However, the region more accurately depicted regional trends relative to one another owing to its consistency in having the lowest pediatric perforated appendix rates. Lastly, this cross-sectional analysis fails to recognize the role of underinsurance, which applies to individuals who has insurance, but does not have the financial means to cover the out-of-pocket expenses associated with healthcare. This is an important consideration when making comparisons of access-related metrics between insured and uninsured children given the prevalence of cost sharing features that accompany public and private insurance plans.
4. Conclusion For children with appendicitis, both geographic region and insurance status appear to be associated with perforation upon presentation. Further investigation is needed to better understand the regional variation in perforated appendicitis rates among children and the role of insurance status on such rates. These insights will inform health policymakers as initiatives within the Affordable Care Act, such as Medicaid expansion, as well as other national and state-level policies continue to evolve.
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