Administrative claims analysis of all-cause annual costs of care and resource utilization by age category for ulcerative colitis patients

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory disease with peak incidence in the third decade of life and a second peak in the sixth or seventh decade. While drug therapy can be used to control the inflammation and reduce symptoms, patients with UC may be treated surgically. There is little information in the published literature evaluating the all-cause health care costs of patients with UC according to age. OBJECTIVE: To assess from administrative claims the direct all-cause (not disease-related) costs of care and resource utilization for patients with UC compared with members without UC by 3 age categories. METHODS: A retrospective analysis was conducted using the PharMetrics database of patients with a diagnosis of UC (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 556.x) from January 1, 2000, through June 30, 2005. This database contains enrollment data and pharmacy and medical claims from more than 85 different managed care organizations and more than 55 million patients in the United States. Patients had to be continuously enrolled for 6 months before and 12 months after the initial UC diagnosis and have at least 2 distinct claims with a diagnosis code for UC. The mean per-patient health care resource utilization and costs were calculated for patients in the year following their initial UC diagnosis and compared with the same measures for a group of age- and gender-matched members (without UC claims) at a ratio of 4:1. Three age groups were analyzed: pediatric-adolescent (aged < 18 years), adults (aged 18 to 64 years), and older adults (aged 65 years). Differences in the measures of all-cause health care resource utilization (claims and costs) between the UC and non-UC groups were tested for statistical significance using the Wilcoxon signed-rank test, a non-parametric alternative to the paired t test. Differences between the 3 age cohorts were tested using the Mann-Whitney U test. RESULTS: Data were collected for 15,105 patients with UC and for 59,159 members in the comparator cohort without UC matched by age and gender. The average age for both cohorts was 44 years, and 54% were female. Mean ([SD], median) annual all-cause total health care costs in 2005 dollars for patients with UC were $13,233 ([$40,715], $5,190) versus $3,214 ([$12,741], $753) for the comparator group (P < 0.001). For all UC patients, all-cause inpatient hospitalization costs constituted the largest component ($5,771, 43.6%) of the mean annual total costs, followed by prescription medications ($2,423, 18.3%); miscellaneous services, such as hospice, psychiatric facility, and nursing home care ($2,092, 15.8%); outpatient hospital visits ($1,310, 9.9%); physician office visits ($899, 6.8%); laboratory procedures ($470, 3.6%); and emergency department visits ($268, 2.0%). Resource utilization (e.g., physician visits, laboratory claims, pharmacy claims) was highest for older adults aged >= 65 years, followed by pediatric-adolescent patients and adults aged 18 to 64 years (all comparisons P < 0.01). The mean ([SD], median) all-cause total health care costs were highest for pediatric-adolescent patients with UC (n = 589, 3.9%) at $23,113 ([$70,999], $6,214), followed by older adults (n = 650, 4.3%) at $15,811 ([$23,882], $6,886, P < 0.001), while adults aged 18 to 64 years (n = 13,866, 91.8%) incurred the lowest cost at $12,693 ([$39,505], $5,108, P < 0.001). CONCLUSION: Patients with UC identified from medical claims incurred significantly higher all-cause health care costs for all 3 age categories than did the comparator group of health plan members without diagnosis for UC.