Test-treatment strategies for patients suspected of having Lyme disease: a cost-effectiveness analysis.
OBJECTIVE
To examine the cost-effectiveness of test-treatment strategies for patients suspected of having Lyme disease.


METHODS
The medical literature was searched for information on outcomes and costs. Expert opinion was sought for information on utilities.


METHODS
Articles that described patient population, diagnostic criteria, dose and duration of therapy, and criteria for assessment of outcomes.


METHODS
The decision analysis evaluated the following strategies: 1) no testing-no treatment; 2) testing with enzyme-linked immunosorbent assay (ELISA) followed by antibiotic treatment of patients with positive results; 3) two-step testing with ELISA followed by Western blot and antibiotic treatment for patients with positive results on either test; and 4) empirical antibiotic therapy. Three patient scenarios were considered: myalgic symptoms, rash resembling erythema migrans, and recurrent oligoarticular inflammatory arthritis. Results were calculated as costs per quality-adjusted life-year and were subjected to sensitivity analysis. Adjustment was made for the diagnostic value of common clinical features of Lyme disease.


RESULTS
For myalgic symptoms without other features suggestive of Lyme disease, the no testing-no treatment strategy was most economically attractive (that is, had the most favorable cost-effectiveness ratio). For rash, empirical antibiotic therapy was less costly and more effective than other strategies. For oligoarticular arthritis with a history of rash and tick bite, two-step testing was associated with the lowest cost-effectiveness ratio. Testing with ELISA and empirical antibiotic therapy cost an additional $880,000 and $34,000 per quality-adjusted life-year, respectively. For oligoarticular arthritis with one or no other features suggestive of Lyme disease, two-step testing was most economically attractive.


CONCLUSIONS
Neither testing nor antibiotic treatment is cost-effective if the pretest probability of Lyme disease is low. Empirical antibiotic therapy is recommended if the pretest probability is high, and two-step testing is recommended if the pretest probability is intermediate.
Nichol
G
G
Ottawa Civic Hospital, Ontario, Canada.
Dennis
D T
DT
Steere
A C
AC
Lightfoot
R
R
Wells
G
G
Shea
B
B
Tugwell
P
P
D000900:Anti-Bacterial Agents / Q000191:economics* / Q000627:therapeutic use*; D015153:Blotting, Western; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008017:Life Expectancy; D008193:Lyme Disease / Q000175:diagnosis / Q000188:drug therapy*; D012680:Sensitivity and Specificity
D000900:Anti-Bacterial Agents