PROVIDENCE, R.I. [Brown University] Most doctors treat Lyme disease with antibiotics for two to four weeks after diagnosis, but if symptoms persist after that, medical guidelines recommend against antibiotic retreatment. That recommendation may not be warranted. A newly published statistical review of the four studies upon which those guidelines are based reports flaws in design, analysis, and interpretation that call into question the strength of the evidence against retreatment.
Allison DeLong, a biostatistician at Brown University's Center for Statistical Sciences and lead author of the study published online Aug. 19, 2012, in Contemporary Clinical Trials, said the four studies do not prove that retreatment does not work. That questionable interpretation, however, has led doctors to forgo treatment and insurance companies to withhold reimbursement.
"The goal of the paper is to clarify what was actually found from these clinical trials and what could be said and what couldn't be said," DeLong said. "A lack of evidence should not be used to deny treatment when the studies have serious flaws."
Evidence in the trials is most often inconclusive, she and three co-authors found. Two studies even found some statistically significant benefits from antibiotics.
DeLong has been curious about Lyme disease retreatment for more than a decade since a friend of hers seemed to benefit from therapy. Her friend paid for the treatment out-of-pocket. Statisticians would call that anecdote an "n of 1," but the example stuck with DeLong as more people, including journalists, began to question whether retreatment really was ineffective.
In 2009 and 2010, DeLong and her colleagues decided to look into the matter with full statistical rigor. Their analysis started by scanning the medical literature for any randomized clinical trials offering evidence of the efficacy of antibiotic retreatment for Lyme disease. Careful review of mo
|Contact: David Orenstein|