Impact of a high-deductible health plan on outpatient visits and associated diagnostic tests.

BACKGROUND: By shifting a greater share of out-of-pocket medical costs to consumers, high-deductible health plans (HDHP) might discourage use of essential outpatient services.
OBJECTIVE: The objective of the study was to examine the impact of an HDHP on outpatient visits and associated laboratory and radiology tests. RESEARCH DESIGN/
SUBJECTS: We used a pre-post with comparison group study design to examine the differential change in outpatient service utilization among 7953 adults who were switched from a traditional Health Maintenance Organization plan to an HDHP compared with 7953 adults remaining in traditional plans. HDHP members had full coverage of preventive laboratory tests and modest copayments for outpatient visits, similar to controls, but faced full cost sharing under the deductible for radiology tests and laboratory tests not classified as preventive.
RESULTS: Compared with controls, the HDHP group experienced moderate relative decreases in overall office visits (incidence rate ratios = 0.91, or a 9% relative reduction; 95% confidence interval: 0.88, 0.94) and visits for higher-priority (0.91; 0.85, 0.97) and lower-priority (0.89; 0.81, 0.99) chronic conditions. There were no significant differences in changes in visit rates for acute higher-priority or lower-priority conditions (both 0.93; 0.86, 1.01) or preventive laboratory tests (0.97; 0.93, 1.02). HDHP members showed moderate relative reductions in the use of general laboratory tests (0.91; 0.86, 0.97) but not radiology tests (0.97; 0.91, 1.03).
CONCLUSIONS: Chronic outpatient visits declined among HDHP members, although preventive laboratory tests and acute visits remained unchanged. HDHP patients with chronic illnesses who have more contact with the health care system might be more likely to reduce utilization because of increased exposure to costs associated with ambulatory visits.