Background: Few studies have investigated the time it takes physicians to follow up abnormal outpatient laboratory results.
Methods: Medical record review of all adult patients seen at a primary care practice between January 2002 and December 2005 with serum potassium results > or = 6.0 mEq/L. We used a proportional hazards model to assess factors associated with time to follow-up for episodes of hyperkalemia.
Results: 259 of 48,333 serum potassium results met inclusion criteria. The median follow-up time was 3 days; after 30 days, 10% of cases had no follow-up. Residing in the same zip code as the clinic (HR = 1.39; P = .029), degree of hyperkalemia (HR = 2.97; P < .001), and renal insufficiency (HR = 1.41; P = .015) were associated with decreased time to repeat testing. Conversely, African Americans (HR = .51; P = .007) had increased time to repeat testing.
Conclusions: Follow-up of abnormal laboratory results in outpatients is suboptimal and research is needed to better understand factors that delay follow-up.