|Empirical parenteral antibiotic treatment of patients with fibromyalgia and fatigue and a positive serologic result for Lyme disease
|Lightfoot R W, Luft B J, Rahn D W, Steere A C, Sigal L H, Zoschke D C, Gardner P, Britton M C, Kaufman R L
This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.
Empirical parenteral therapy for patients with Lyme disease.
Economic study type
Patients in endemic areas with chronic fatigue and myalgia and a positive serologic result for Lyme disease.
Primary care. The study was conducted in the USA.
Dates to which data relate
Source of effectiveness data
Review of previous studies.
Outcomes assessed in the review
False positive rates and toxicity rates due to treatment.
Study designs and other criteria for inclusion in the review
Decisions on the relevance of the studies were based on the methods followed for patient selection and classification, diagnosis criteria, health technology involved and the criteria on which responses to therapy were ascertained.
Sources searched to identify primary studies
Peer-reviewed journals and published epidemiologic reports were included.
Criteria used to ensure the validity of primary studies
Methods used to judge relevance and validity, and for extracting data
Consensus by authors was used for judging relevance and validity of primary studies.
Number of primary studies included
Methods of combining primary studies
Investigation of differences between primary studies
Results of the review
In a population of 100,000, 2% will have the fatigue and myalgia syndrome due to causes other than Lyme disease. Of these, 2% will be falsely seropositive for Lyme disease.
If all seropositive patients were treated with antibiotics for the possibility of Lyme disease, 3% will develop minor toxicity and 0.052 patients will develop major drug reaction. Thus the empirical strategy will cause 29 cases of drug toxicity for each case occurring using the alternative strategy.
Measure of benefits used in the economic analysis
Cases of late Lyme disease prevented or cured.
Costs and quantities were not reported separately. Health service and patients' costs were considered. Costs involved actual treatment costs: drugs, professional fee and other charges relating to drug administration. Costs of treating side-effects were included, as well as anxiety costs to the patients due to untreated positive test results and costs of inconvenience of therapy, for example, pain. No price date was given. Costs were not discounted.
Costs and quantities were not reported separately. The amount the patient is willing to pay to avoid the time involved in treatment was considered. Costs were not discounted. No price date was given.
One-way simple sensitivity analyses and threshold analysis were conducted varying the base assumptions - on the incidence of Lyme disease, occurrence of false-positives, risk of late central nervous system or joint disease, prevalence of seropositivity and the risk of late Lyme disease, the incidences of major and minor side effects and the dollar value assigned to the anxiety experienced by a patient.
Estimated benefits used in the economic analysis
The number of late Lyme diseases prevented with empirical antibiotic treatment was estimated to be 1.8 in a population of 100,000 in the most endemic area.
Under baseline assumptions for a population of 100,000 total cost of the strategy with empirical antibiotics was $187,694. Total cost of the strategy without empirical antibiotics was $32,498. Therefore the latter produced a saving of resources of $155,196.
Synthesis of costs and benefits
The authors estimated that it would cost $86,221 (incremental cost-effectiveness ratio) to prevent one case of late Lyme disease if all seropositive patients with fatigue and myalgia in the most endemic region were treated with intravenous antibiotics. Only when the risk for late Lyme disease was estimated to be 87% or if patients were willing to pay $3,485 for relief of their anxiety did the empirical strategy break even.
For most patients with a positive Lyme antibody titer whose only symptoms were nonspecific myalgia or fatigue the risks and costs of empirical parenteral antibiotic therapy exceeded the benefits.
The study results seem to be informative, but most of the baseline assumptions were subjective guesses. Hence these results should be used with caution, taking into consideration the assumptions the authors have made in arriving at these figures. The analysis suffered from not giving any dates.
Modelling analysis could havebeen useful to simulate the evolutionary path of the disease and to clarify the impact on final costs and benefits.
Finally, the reader should consider that given the data, the generalisability of this analysis may be limited to poulations of endemic regions.
Lightfoot R W, Luft B J, Rahn D W, Steere A C, Sigal L H, Zoschke D C, Gardner P, Britton M C, Kaufman R L. Empirical parenteral antibiotic treatment of patients with fibromyalgia and fatigue and a positive serologic result for Lyme disease. Annals of Internal Medicine 1993; 119: 503-509
Subject indexing assigned by NLM
Anti-Bacterial Agents /administration & Cost-Benefit Analysis; Drug Administration Schedule; Drug Costs; Fatigue Syndrome, Chronic /drug therapy /etiology; Fibromyalgia /drug therapy /etiology; Humans; Infusions, Intravenous; Lyme Disease /complications /drug therapy /economics /epidemiology; Prevalence; United States /epidemiology; dosage /adverse effects /economics
Date bibliographic record published
Date abstract record published