Treatments and Corresponding Costs of Prostate Cancer
Hospital claims data from the Premier Perspective Database were used to conduct the analyses. This database is the largest hospital database in the USA for determining hospital quality benchmarking and contains linked, de-identified inpatient medical, pharmacy and billing data from more than 500 geographically dispersed hospitals. Participating hospitals represent all regions of the USA, are predominantly small- to mid-sized nonteaching facilities and serve largely urban populations. The database contains a date-stamped log of all billed items by cost accounting department, including medications and laboratory, diagnostic and therapeutic services, as well as primary and secondary diagnoses for each patient. In addition, de-identified, linked patient enrollment data, including demographic and payer information, as well as provider characteristics, are available in the discharge summary file.
Encounters associated with prostate cancer (International Classification of Diseases, 9th Revision [ICD-9] codes185.xx [malignant neoplasm of the prostate], 233.4 [carcinoma in situ, prostate]) between 1 January 2006 and31 December 2010 were eligible for study inclusion. Encounters were also required to be associated with a patient who was ≥40 years of age and had at least one PCa-related treatment during the hospitalization or outpatient visit. PCa treatment was defined as the presence of a code or claim (e.g., Current Procedural Terminology [CPT] code, Healthcare Common Procedure Coding System [HCPCS] or hospital billing code) for prostate surgery, radiation treatment, chemotherapy, hormone therapy, radiopharmaceuticals or alternative treatments for prostate cancer (ketoconazole, aminoglutethimide, corticosteroid). All PCa-related treatments were independently reviewed by a radiation oncologist prior to inclusion in the analysis. Encounters were excluded if they had codes indicative of additional cancers (ICD-9 codes 140.xx–172.xx, 174.xx–184.xx, 186.xx, 187.xx, 189.xx–195.xx and 199.xx–208.xx).
The primary variables of interest were treatments utilized within the hospital stay or outpatient visit, the corresponding costs of treatments per hospitalization or visit and the length of stay. For the purpose of this analysis, the unit of analysis was the hospital encounter which included inpatient hospital stays and hospital-based outpatient visits. To provide a comprehensive description of where costs are incurred, costs were aggregated by the department billing for services. Descriptive summary statistics were constructed as frequencies and proportions for categorical data and means for continuous variables. Statistical analyses were conducted in SAS version 9.2.1 (SAS Business Analytics, NC, USA).
Methods
Data Source
Hospital claims data from the Premier Perspective Database were used to conduct the analyses. This database is the largest hospital database in the USA for determining hospital quality benchmarking and contains linked, de-identified inpatient medical, pharmacy and billing data from more than 500 geographically dispersed hospitals. Participating hospitals represent all regions of the USA, are predominantly small- to mid-sized nonteaching facilities and serve largely urban populations. The database contains a date-stamped log of all billed items by cost accounting department, including medications and laboratory, diagnostic and therapeutic services, as well as primary and secondary diagnoses for each patient. In addition, de-identified, linked patient enrollment data, including demographic and payer information, as well as provider characteristics, are available in the discharge summary file.
Sample Selection
Encounters associated with prostate cancer (International Classification of Diseases, 9th Revision [ICD-9] codes185.xx [malignant neoplasm of the prostate], 233.4 [carcinoma in situ, prostate]) between 1 January 2006 and31 December 2010 were eligible for study inclusion. Encounters were also required to be associated with a patient who was ≥40 years of age and had at least one PCa-related treatment during the hospitalization or outpatient visit. PCa treatment was defined as the presence of a code or claim (e.g., Current Procedural Terminology [CPT] code, Healthcare Common Procedure Coding System [HCPCS] or hospital billing code) for prostate surgery, radiation treatment, chemotherapy, hormone therapy, radiopharmaceuticals or alternative treatments for prostate cancer (ketoconazole, aminoglutethimide, corticosteroid). All PCa-related treatments were independently reviewed by a radiation oncologist prior to inclusion in the analysis. Encounters were excluded if they had codes indicative of additional cancers (ICD-9 codes 140.xx–172.xx, 174.xx–184.xx, 186.xx, 187.xx, 189.xx–195.xx and 199.xx–208.xx).
Analysis of Outcomes
The primary variables of interest were treatments utilized within the hospital stay or outpatient visit, the corresponding costs of treatments per hospitalization or visit and the length of stay. For the purpose of this analysis, the unit of analysis was the hospital encounter which included inpatient hospital stays and hospital-based outpatient visits. To provide a comprehensive description of where costs are incurred, costs were aggregated by the department billing for services. Descriptive summary statistics were constructed as frequencies and proportions for categorical data and means for continuous variables. Statistical analyses were conducted in SAS version 9.2.1 (SAS Business Analytics, NC, USA).