Diabetes, kidney disease and cardiovascular disease patients. Assessing care of complex patients using outpatient testing and visits: additional metrics by which to evaluate health care system functioning.

BACKGROUND: The triad of cardiovascular disease (CVD), chronic kidney disease (CKD) and diabetes mellitus (DM) share many fundamental disease pathways. Patients with these conditions contribute excessively to health care costs. Opportunities for system redesign require metrics by which to evaluate the impact.
METHODS: Using a provincial comprehensive set of administrative billing databases (outpatient visits, laboratory tests, pharmacy and hospital inpatient services), we itemized the prevalence of each and combination of conditions, resource utilization associated with each condition and combinations, using ICD 9-10 billing codes and standard definitions. Three consecutive years (2003-2005) were used to establish stability of findings.
RESULTS: CKD, CVD and DM diagnoses are found in 422 124 persons within a province of 4.3 million individuals (10%); 1.7% had all three conditions. The median age of each cohort varied significantly between those with multiple conditions (67-79 years) versus those with single condition (56-72 years). The median number of physician visits was 26 per patient year. Duplicate testing accounted for expenditures of $3 million/annum; 7.55% of patients accounted for 34.4% of duplicate tests. Those with DM or CKD had similar use of medications, physician visits and hospital days. Those with all conditions (CVD-CKD-DM) had a median of 6 in-hospital days/year. A significant proportion were not on ACE/ARB or statin medications (30 and 45%, respectively).
CONCLUSION: Patients with chronic, complex conditions consume a large number of outpatient and inpatient resources. Documenting these allows identification of a set of metrics by which to design and measure health care system redesign initiatives. Potential targets to benchmark in designing more effective systems have been identified.