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Keywords:

  • prostatic neoplasms;
  • prostatectomy;
  • complication, insurance, Medicare, Medicaid

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. FUNDING SUPPORT
  8. CONFLICTS OF INTEREST DISCLOSURES
  9. REFERENCES

BACKGROUND:

Private insurance status may favorably affect various health outcomes including those associated with radical prostatectomy (RP). We explored the effect of insurance status on 5 short-term RP outcomes.

METHODS:

Within the Health Care Utilization Project Nationwide Inpatient Sample (NIS) we focused on RPs performed within the 5 most contemporary years (2003-2007). We tested the rates of blood transfusions, extended length of stay, intraoperative and postoperative complications, as well as in-hospital mortality, stratified according to insurance status. Multivariable logistic regression analyses, fitted with general estimation equations for clustering among hospitals, adjusted for confounding factors.

RESULTS

Overall, 61,167 RPs were identified. Of those, private insurance accounted for the majority of cases (n = 41,312, 67.5%), followed by Medicare (n = 18,759, 30.7%) and Medicaid (n = 1096, 1.8%). Insurance status other than private was associated with higher rates of blood transfusions (P < .001), higher overall postoperative complication rates (P < .001), higher rates of hospital stay above the median (P < .001), as well as higher in-hospital mortality (P = .01). In multivariable analyses, compared with patients with private insurance, Medicaid patients had higher rates of blood transfusion (odds ratio [OR] = 1.45, P < .001), length of stay beyond the median (OR = 1.61, P < .001) postoperative complications (OR= 1.24, P = .02), and in-hospital mortality (OR = 4.91, = .01). Similarly, Medicare patients had higher rates of blood transfusions (OR = 1.21, P < .001), overall postoperative complications (OR = 1.17, P×< .001) and length of stay beyond the median (OR = 1.25, P < .001).

CONCLUSIONS:

Even after adjusting for confounding factors, patients with private insurance have better outcomes than their counterparts with nonprivate insurance. Cancer 2012;. © 2011 American Cancer Society.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. FUNDING SUPPORT
  8. CONFLICTS OF INTEREST DISCLOSURES
  9. REFERENCES

Radical prostatectomy (RP) represents the standard of care among management options for patients with clinically localized prostate cancer.1 Morbidity and mortality rates of this procedure have improved significantly within the last decade.2 Surgeon and hospital caseloads represent established predictors of a variety of prostatectomy outcomes, according to the “practice makes perfect” hypothesis.3-5 Other predictors of adverse outcomes consist of older patient age, unfavorable baseline comorbidity profile, and select geographical region.2

Health insurance status may represent another important albeit underestimated predictor of RP outcomes. Unfortunately, there is currently no study examining the relationship between insurance status and outcomes in the context of prostate cancer. Specifically, the association between insurance status and adverse RP outcomes has not been elucidated. We hypothesized that the advantages of private health care might favorably affect the outcome of these patients and examined this relationship within a large contemporary (2003-2007) population-based cohort of individuals undergoing RPs.

MATERIALS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. FUNDING SUPPORT
  8. CONFLICTS OF INTEREST DISCLOSURES
  9. REFERENCES

Data Source

Data from the most contemporary years (2003-2007) of the Nationwide Inpatient Sample (NIS) were abstracted. The NIS includes inpatient discharge data collected via federal-state partnerships, as part of the Agency for Health care Research and Quality's Health care Cost and Utilization Project. As of the year 2007, the NIS contained administrative data on 8,043,415 discharges from 1044 hospitals within 40 states, approximating 20% of community hospitals within the United States, including public hospitals and academic medical centers. The NIS is the sole hospital database in the United States with charge information on all patients regardless of payer, including persons covered by Medicare, Medicaid, private insurance, and the uninsured.

Sample Population and Surgical Procedures

Relying on discharge records, all patients with a primary diagnosis of prostate cancer (ICD-9-CM code 185) were considered for the study. The prostatectomy procedure code (ICD-9-CM 60.5) resulted in the identification of 63,827 patients who underwent RP between 2003 and 2007.

Baseline Patient and Hospital Characteristics

For all patients, the following variables were available: age, year of surgery, race (White vs Black vs other vs unknown), Charlson Comorbidity Index (CCI), annual hospital caseload (AHC) tertiles, academic status, hospital region, and insurance status. Information about hospital region was obtained from the American Hospital Association Annual Survey of Hospitals, and defined by the United States Census Bureau.6 This comprised of the following: South (Delaware, Maryland, District of Columbia, Virginia, Carolina, Georgia, Florida, Kentucky, Tennessee, Alabama, Mississippi, Arkansas, Louisiana, Oklahoma, Texas), West (Montana, Idaho, Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, Washington, Oregon, California, Alaska, Hawaii), Northeast (Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania), and Midwest (Ohio, Indiana, Illinois, Michigan, Wisconsin, Minnesota, Iowa, Missouri, Dakota, Nebraska, Kansas). CCI was derived from ICD-9 codes according to previously established criteria7 and was stratified according to 2 levels: 0 versus ≥1. AHC was defined according to the number of procedures performed at each participating institution during each study calendar year. Hospitals were divided into caseload tertiles, including low—34 or fewer, intermediate—35 to 90, and high—91 or greater RPs. Hospitals were divided into academic and nonacademic institutions. The hospital's academic status was obtained from the AHA Annual Survey of Hospitals. A hospital is considered to be a teaching hospital if it has an American Medical Association (AMA)-approved residency program, is a member of the Council of Teaching Hospitals, or has a ratio of full-time equivalent interns and residents to beds of 0.25 or higher. To ensure uniformity of coding across data sources, detailed insurance categories are combined into general groups, namely, private insurance, Medicare, Medicaid, and self-pay. In particular, private insurance includes Blue Cross, commercial carriers, private health maintenance organizations (HMO), and preferred provider organizations (PPO). Medicare includes both fee-for-service and managed care Medicare patients; Medicaid includes both fee-for-service and managed care Medicaid patients.

Intraoperative, Postoperative Complications, and Blood Transfusions During Hospitalization

The NIS records up to 15 diagnoses and procedures per in-hospital stay. The presence of any complication was defined using ICD-9 diagnoses 2 through 15. The specific ICD-9 codes used for homologous blood transfusions, intraoperative, and postoperative complications are described in Table 1. According to previous reports postoperative complications consisted of potentially life-threatening cardiac, respiratory, or vascular events, miscellaneous medical and surgical events, and other events, such as genitourinary complications and wound infection.8, 9 For the purpose of statistical analysis, we stratified patients by 0 versus 1 or greater complications during hospitalization. We used the same stratification for homologous blood transfusion rate analysis.

Table 1. ICD9 Diagnosis and Procedure Codes
Type of OutcomeCategoryDiagnosis CodesProcedure Codes
Postoperative complicationsCardiac410.xx, 402.01, 402.11, 402.91, 428.xx, 427.5, 997.1 
Respiratory518.0, 514, 518.4, 466.xx, 480.xx, 481, 482.xx, 483.xx, 485, 486, 518.5, 518.81, 518.82, 799.1, 997.3 
Genitourinary590.1x, 590.2, 590.8x, 590.9, 591, 593.3, 593.4, 593.5, 593.81, 593.82, 595.89, 596.1, 596.2, 596.6, 997.555.02, 55.03, 55.12, 55.93, 55.94, 59.93, 97.61, 97.62
Wound567.xx, 998.3, 998.5x, 998.6, 998.8354.61, 54.1x, 54.91, 54.0, 59.19
Vascular415.1, 451.1x, 451.2, 451.81, 451.9, 453.8, 453.9, 997.2, 999.2, 444.22, 444.81, 433.xx, 434.xx, 436, 437.xx 
Miscellaneous MedicalICD9: 584.xx, 586, 785.5x, 995.0, 995.4, 998.0, 999.4, 999.5, 999.6, 999.7, 999.8, 457.8, 560.1, 560.8x, 560.9, 997.4, 353.0, 354.2, 723.4, 955.1, 955.3, 955.7, 955.8, 955.9, 593.4, 531.xx, 532.xx, 533.xx, 782.4, 573.8 
Miscellaneous Surgical599.1, 596.1, 596.6, 565.1, 569.3, 569.4x, 604.0, 998.1x, 998.4, 998.7, 998.9, E870.0, E870.4, E870.7, E870.8, E870.9, E871.0, E873.0, E876.0 
Homologous blood transfusion  99.04
Intraoperative complicationsBowel 46.03, 46.04, 46.10, 46.11, 46.14, 48.4, 48.5, 48.6, 48.7, 48.9
Ureter 56.1, 56.41, 56.74, 56.75, 56.81, 56.84, 56.86, 56.89, 56.91;
Nerve/Vessel956.0, 956.1, 956.4, 956.5, 956.8, 956.9, 902.50, 902.51, 902.52, 902.53, 902.54, 902.59, 998.2 

Length of Stay and In-Hospital Mortality

Length of stay, provided by the NIS, is calculated by subtracting the admission date from the discharge date. Length of stay was dichotomized according to the median (≤3 vs. >3 days). In-hospital mortality information is coded from disposition of patient. Patients with missing or invalid length of stay or in-hospital mortality status were not considered within the current study.

Statistical Analysis

Descriptive statistics focused on frequencies and proportions for categorical variables. Means, medians, and ranges were reported for continuously coded variables. Chi-square and independent-sample t tests were used to compare the statistical significance of differences in proportions and means, respectively.

The first part of the statistical analyses focused on rates of blood transfusion, intraoperative complications, postoperative complications, prolonged length of stay, and in-hospital mortality according to patient's insurance type.

In the second part of our analysis, we relied on multivariable logistic regression models to quantify the effect of insurance status on 14 different outcomes. These consisted of the odds of receiving 1) a homologous blood transfusion and 2) overall intraoperative complication. 3) Within intraoperative complications, separate models focused on the prediction of bowel laceration, 4) ureteral injury, and 5) nerve and/or vessel injury. Moreover, we performed a separate analysis for prediction of 6) overall postoperative complication and also targeted the 6 subtypes of postoperative complications, namely, 7) cardiac, 8) respiratory, 9) genitourinary, 10) wound, 11) vascular, 12) miscellaneous medical, and 13) miscellaneous surgical complications. Moreover, the same analysis was performed for 14) prediction of length of stay beyond the median. All models relied on generalized estimating equations (GEE models) to further adjust for clustering among hospitals.10

All tests were 2 sided with a statistical significance set a P < .05. Analyses were conducted using the R statistical package (the R foundation for Statistical Computing, version 1.33).

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. FUNDING SUPPORT
  8. CONFLICTS OF INTEREST DISCLOSURES
  9. REFERENCES

Between 2003 and 2007, 63,827 radical prostatectomies were recorded within the National Inpatient Sample. We focused our analyses on the 61,167 patients with either private, Medicare, or Medicaid insurance status treated at 1083 institutions. Baseline characteristics of patients undergoing RP in the NIS between 2003 and 2007 are listed in Table 2. Within our cohort, the majority of patients (67.5%) were covered by private insurance, 30.7% Medicare, and 1.8% Medicaid. In comparison to privately insured patients, Medicare patients were older (mean age 68.0 vs 58.0, P < .001), had more comorbidities according to CCI ≥1 (26.3% vs 17.6%, P < .001), were less likely to be treated at high AHC institutions (32.1% vs 39.3%, P < .001), and were less likely to be treated at academic institutions (52.5% vs 61.2%, P < .001).

Table 2. Demographic Characteristics of Patients Treated with Radical Prostatectomy for Prostate Cancer, Stratified According to Insurance Status, Nationwide Inpatient Sample, 2003 to 2007
 PrivateMedicareMedicaidP
  • Abbreviation: CCI, Charlson Comorbidity Index.

  • a

    Total number of institutions = 1083 (the categories are not exclusive).

  • b

    Includes Asian, Pacific Islander, Native American, other unspecified.

  • c

    Based on Comorbidity developed by Charlson et al and adapted by Deyo et al.

  • d

    Hospital region is defined by the US Census Bureau.

No. of patients41,31218,7591096 
No. of institutionsa1015940297 
Mean age (median)58.0 (58.0)68.0 (68.0)58.5 (59.0)<.001
 Range28-8938-8837-77 
Race    
 White23,543 (57.0)11,381 (60.7)343 (31.3)<.001
 Black3,450 (8.4)1,232 (6.6)242 (22.1) 
 Otherb2,712 (6.6)1,281 (6.8)249 (22.7) 
 Missing11,607 (28.1)4,865 (25.9)262 (23.9) 
CCIc    
 034,057 (82.4)13,826 (73.7)766 (69.9)<.001
 ≥17,255 (17.6)4,933 (26.3)330 (30.1) 
Annual hospital caseload    
 1st tertile12,005 (29.1)6,579 (35.1)457 (41.7)<.001
 2nd tertile13,069 (31.6)6,161 (32.8)361 (32.9) 
 3rd tertile16,238 (39.3)6,019 (32.1)278 (25.4) 
Hospital regiond    
 Northeast7,966 (19.3)2,693 (14.4)439 (40.1)<.001
 Midwest9,773 (23.7)4,482 (23.9)134 (12.2) 
 South14,243 (34.5)6,934 (37.0)246 (22.4) 
 West9,330 (22.6)4,650 (24.8)277 (25.3) 
Institutional academic status    
 Nonteaching16,039 (38.8)8,908 (47.5)359 (32.8)<.001
 Teaching25,273 (61.2)9,851 (52.5)737 (67.2) 

In comparison to privately insured patients, Medicare patients had higher rates of blood transfusions (7.8% vs 5.4%, P < .001) and postoperative complications (13.2% vs 9.7%, P < .001) (Table 3). Specifically, the rates of cardiac (2.0% vs 0.9%, P < .001), respiratory (2.6% vs 1.8%, P < .001), vascular (0.7% vs 0.3%, P < .001), genitourinary (1.1% vs 0.9%, P = .02), miscellaneous medical (6.4% vs 5.0%, P < .001), and miscellaneous surgical (3.0% vs 2.6%, P =.006) complications were higher in Medicare patients compared with privately insured patients. Medicare patients also had higher rates of length of stay beyond the median (23.7% vs 16.9%, P < .001) and in-hospital mortality (0.1% vs 0.0%, P = .005). Medicaid patients likewise experienced an increased likelihood of adverse outcomes (Table 3).

Table 3. Intraoperative and Postoperative Outcomes During Hospitalization Stratified by Insurance Status
 PrivateMedicareMedicaidP
No. of patients41,312187591096
Blood transfusion2219 (5.4)1468 (7.8)117 (10.7)<.001
Intraoperative complication536 (1.3)290 (1.5)20 (1.8).05
Postoperative complication    
 Overall4017 (9.7)2479 (13.2)141 (12.9)<.001
 Cardiac352 (0.9)374 (2.0)20 (1.8)<.001
 Respiratory733 (1.8)485 (2.6)24 (2.2)<.001
 Vascular135 (0.3)131 (0.7)9 (0.8)<.001
 Operative wound159 (0.4)80 (0.4)6 (0.5).6
 Genitourinary384 (0.9)208 (1.1)18 (1.6).03
 Miscellaneous medical2045 (5.0)1196 (6.4)63 (5.7)<.001
 Miscellaneous surgical1058 (2.6)560 (3.0)39 (3.6).008
Length of stay >3 days6964 (16.9)4446 (23.7)339 (30.9)<.001
In-hospital mortality20 (0.0)16 (0.1)3 (0.3).01

In multivariable analyses adjusted for clustering (Table 4a–4d), Medicare patients were at higher risk of receiving a blood transfusion (odds ratio [OR] = 1.21, P < .001), of experiencing any postoperative complication (OR = 1.17, P < .001) and to stay in-hospital for more than 2 days (OR = 1.25, P < .001). Similarly, Medicaid patients were more likely to be transfused (OR = 1.45, P < .001), to stay in-hospital for more than 2 days (OR = 1.61, P < .001), to experience any postoperative complication (OR = 1.24, P = .02) and to die during the hospitalization (OR= 4.91, P = .01) when compared with private insurance patients. In those models, AHC also achieved independent predictor status. Specifically, RP performed at high AHC hospitals were less frequently associated with intraoperative (OR = 0.69, P = .001) or postoperative complications (OR = 0.62, P < .001), less frequently resulted in length of stay beyond the median (OR = .18, P < .001) and were associated with fewer blood transfusions (OR = 0.35, P < .001). Table 4b–4d shows the multivariable analyses within each AHC tertile.

Table 4a. All Institutions: Multivariable Analyses of Adverse Outcomes Following RP at All Institutions Adjusted for Age, Race, CCI, Hospital Region, Annual Hospital Caseload, and Institutional Academic Status
 Medicare vs PrivatePMedicaid vs PrivateP
  1. Abbreviations: CCI, Charlson Comorbidity Index; RP, radical prostatectomy.

Homologous blood transfusion1.21 (1.10-1.32)<.0011.45 (1.19-1.78)<.001
Intraoperative complication1.07 (0.88-1.29).61.33 (0.84-2.09).2
Postoperative complication    
 Overall1.17 (1.09-1.25)<.0011.24 (1.03-1.49).02
 Cardiac1.54 (1.26-1.87)<.0011.67 (1.05-2.66).03
 Respiratory1.18 (1.01-1.38).041.07 (0.7-1.62).8
 Vascular1.16 (0.84-1.59).42.41 (1.21-4.79).01
 Operative wound0.98 (0.69-1.39).91.28 (0.56-2.94).6
 Genitourinary1.08 (0.86-1.35).51.72 (1.06-2.79).03
 Miscellaneous medical1.08 (0.98-1.19).11.08 (0.83-1.40).6
 Miscellaneous surgical1.07 (0.93-1.22).41.31 (0.94-1.82).1
Length of stay >3 days1.25 (1.18-1.33)<.0011.61 (1.40-1.85)<.001
In-hospital mortality0.82 (0.35-1.91).64.91 (1.39-17.35).01
Table 4b. Low Annual Hospital Caseload: Multivariable Analyses of Adverse Outcomes Following RP at Low AHC Institutions, Adjusted for Age, Race, CCI, Hospital Region, and Institutional Academic Status
 Medicare vs PrivatePMedicaid vs. PrivateP
  1. Abbreviations: AHC, annual hospital caseload; CCI, Charlson Comorbidity Index; RP, radical prostatectomy.

Homologous blood transfusion1.31 (1.15-1.49)<.0011.62 (1.24-2.12)<.001
Intraoperative complication1.08 (0.79-1.46).61.92 (1.09-3.39).02
Postoperative complication    
 Overall1.18 (1.05-1.32).0041.51 (1.18-1.94).001
 Cardiac1.71 (1.26-2.33).0011.65 (0.82-3.30).2
 Respiratory1.22 (0.97-1.55).11.48 (0.89-2.47).1
 Vascular0.87 (0.54-1.42).62.70 (1.13-6.50).03
 Operative wound1.49 (0.84-2.63).22.86 (1.00-8.2).05
 Genitourinary1.21 (0.82-1.79).43.39 (1.88-6.11)<.001
 Miscellaneous medical1.10 (0.94-1.28).31.26 (0.88-1.79)0.2
 Miscellaneous surgical1.06 (0.85-1.31).61.48 (0.94-2.31).1
Length of stay >3 days1.33 (1.23-1.45)<.0011.84 (1.52-2.23)<.001
In-hospital mortality0.62 (0.14-2.68).57.27 (1.29-40.76).02
Table 4c. Intermediate Annual Hospital Caseload: Multivariable Analyses of Adverse Outcomes Following RP at Intermediate AHC Institutions, Adjusted for Age, Race, CCI, Hospital Region, and Institutional Academic Status
 Medicare vs. PrivatePMedicaid vs. PrivateP
  • Abbreviations: AHC, annual hospital caseload; CCI, Charlson Comorbidity Index; RP, radical prostatectomy.

  • a

    Numbers to low for meaningful conclusion.

Homologous blood transfusion1.01 (0.85-1.20).941.25 (0.84-1.84).3
Intraoperative complication1.38 (0.98-1.93).060.90 (0.33-2.47).8
Postoperative complication    
 Overall1.18 (1.04-1.34).0090.91 (0.64-1.30).6
 Cardiac1.26 (0.90-1.78).21.51 (0.65-3.51).3
 Respiratory1.05 (0.80-1.37).70.50 (0.19-1.37).2
 Vascular1.45 (0.84-2.51).21.55 (0.37-6.48).6
 Operative wound0.94 (0.49-1.79).91.06 (0.25-4.46).9
 Genitourinary1.03 (0.68-1.56).90.90 (0.28-2.88).9
 Miscellaneous medical1.05 (0.88-1.25).60.67 (0.39-1.15).2
 Miscellaneous surgical1.20 (0.94-1.54).151.26 (0.68-2.34).5
Length of stay >3 days1.17 (1.05-1.29).0041.29 (1.00-1.67).05
In-hospital mortality0.75 (0.22-2.50).6aa
Table 4d. High Annual Hospital Caseload: Multivariable Analyses of Adverse Outcomes Following RP at High AHC Institutions, Adjusted for Age, Race, CCI, Hospital Region, and Institutional Academic Status
 Medicare vs PrivatePMedicaid vs PrivateP
  • Abbreviations: AHC, annual hospital caseload; CCI, Charlson Comorbidity Index; RP, radical prostatectomy.

  • a

    Numbers to low for meaningful conclusion.

Homologous blood transfusion1.22 (1.00-1.48).051.39 (0.82-2.38).2
Intraoperative complication0.79 (0.56-1.13).20.69 (0.17-2.81).6
Postoperative complication    
 Overall1.13 (0.99-1.29).081.21 (0.78-1.87).4
 Cardiac1.68 (1.14-2.48).0092.36 (0.94-5.93).07
 Respiratory1.28 (0.93-1.77).11.15 (0.36-3.66).8
 Vascular1.27 (0.64-2.52).51.80 (0.24-13.51).6
 Operative wound0.55 (0.28-1.06).08aa
 Genitourinary1.03 (0.71-1.48).90.35 (0.05-2.51).3
 Miscellaneous medical1.09 (1.09-1.31).41.47 (0.83-2.61).2
 Miscellaneous surgical0.93 (0.72-1.2).61.05 (0.46-2.39).9
Length of stay >3 days1.21 (1.05-1.39).0061.73 (1.19-2.51).004
In-hospital mortality2.03 (0.25-16.43).5aa

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. FUNDING SUPPORT
  8. CONFLICTS OF INTEREST DISCLOSURES
  9. REFERENCES

RP is considered as the gold standard treatment for localized prostate cancer. Numerous reports indicate that insurance is associated with decreased access to health care screening and treatment resources as well as increased risk-adjusted morbidity and mortality.11-15 However, the effect of insurance status on short-term adverse outcomes has never been assessed for individual urological procedures. Based on this consideration, we evaluated the effect of insurance status on several short-term outcomes in a large contemporary (2003-2007) population-based cohort of individuals undergoing RP.

Our results demonstrate several important points. Within our dataset, 1083 institutions were included in this study, of which 1015 (93.7%) treated patients with private insurance, 940 (86.8%) treated patients with Medicare, and only 297 (27.4%) treated patients with Medicaid. Moreover, private insurance holders are treated at centers with substantially higher institutional volumes; only 29.1% of private insurance RPs versus 41.7% of Medicaid RPs were performed at low AHC institutions. Taken together, these observations suggest a higher ratio of surgeons per institution or more subspecialized practice profile for private insurance RPs. It is also likely that this discrepancy indicates surgeons and hospitals preferentially treat patients that bring in a higher rate of reimbursement.

It could be postulated that better outcomes associated with private insurance directly result from the volume effect. The persistence of the statistically significant relationship between insurance status and complication rates and length of stay, after adjustment for AHC, clearly indicates that the effect of insurance status is independent of AHC (Table 4a). This means that the benefits of private insurance reach beyond the “practice makes perfect” hypothesis. Nonetheless, our study does corroborate previous findings documenting the effect of AHC on RP outcomes.16-19 Specifically, RP performed at high AHC hospitals were associated with fewer blood transfusions, were less frequently associated with intraoperative or postoperative complications, and less frequently resulted in length of stay beyond the median.

Table 4b–4d demonstrates the complex link between AHC and insurance status. As the AHC increases, the OR for virtually all adverse outcomes decreases. This protective effect is most pronounced in the Medicaid population, which is the least likely to be treated in high-volume centers. These findings highlight the importance of the regionalization of oncologic procedures in urology.20 It also emphasizes the need for multivariable adjustment for institutional volume, when insurance status is examined. Lack of adjustment for institutional volume could lead to important confounding.

Direct comparisons of length of stay, as well as complication and transfusion rates showed better outcomes for private patients in virtually all of the examined endpoints. However, important population differences may account for the observed differences. Specifically, Medicaid/Medicare patients might have decreased access to screening and/or could represent older and/or sicker individuals. Therefore, we performed a multivariable adjustment for the key patient and institutional characteristics, namely, AHC, age, race, CCI, hospital region, and institutional academic status. In adjusted analyses, we demonstrated the following: in comparison to private insurance, Medicare patients are 21% more likely to receive a blood transfusion, 17% more likely to experience any postoperative complication, and 25% more likely to stay beyond the median. Similarly, Medicaid patients are 45% more likely to receive a blood transfusion, 24% more likely to experience any postoperative complication, 61% more likely to stay beyond the median, and at a 5-fold higher risk of in-hospital mortality.

The importance of insurance status for various medical and surgical outcomes has previously been addressed. Several authors have reported better complication and mortality rates when patients are privately insured. However, the reported disparities were often assessed in unadjusted statistical analyses. Differences in patient characteristics, such as age and CCI, may have spuriously inflated the observed differences. Consequently, adjusted multivariable models should ideally accompany this type of analyses. To the best of our knowledge, only a few studies have reported improved short-term adverse outcomes in private insurance patients after multivariable adjustment.11, 12, 14 For example, LaPar et al13 demonstrated that Medicaid insurance status was associated with the longest length of stay and highest total costs, whereas Medicaid and uninsured insurance status independently conferred the highest adjusted risks of mortality in patients undergoing major surgical operations. Similarly, Shen et al15 reported that uninsured patients had a higher level of neurologic impairment, a longer average length of hospital stay, and higher mortality risk after an acute ischemic stroke.

Limitations of the current study include the selection bias related to the database: only 20% of the US population is represented in the National Inpatient Sample. Unavailability of individual surgical volume represents another limitation. Ideally, our analyses would have controlled for this important variable. In addition, administrative records may underestimate the rate of any transfusion type. Specifically, a 17% underestimation was previously reported relative to blood bank records.27 Moreover, our mortality estimates are based on in-hospital rates. It is possible that the true mortality is therefore underestimated, as some patients may have died at other institutions where their mortality was not captured.

In conclusion, private RPs are invariably associated with better outcomes than their public insurance counterparts, even after adjusting for confounding factors. Public policy should promote higher quality of care to all patients independent of insurance status.

FUNDING SUPPORT

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. FUNDING SUPPORT
  8. CONFLICTS OF INTEREST DISCLOSURES
  9. REFERENCES

Pierre I. Karakiewicz is partially supported by the University of Montreal Health Centre Urology Specialists, Fonds de la Recherche en Sante du Quebec, the University of Montreal Department of Surgery and the University of Montreal Health Centre (CHUM) Foundation. No other specific funding was disclosed.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. FUNDING SUPPORT
  8. CONFLICTS OF INTEREST DISCLOSURES
  9. REFERENCES