International Journal of General Medicine September 4th, 2017
Purpose: Lyme disease is spreading worldwide, with multiple Borrelia species causing a broad
range of clinical symptoms that mimic other illnesses. A validated Lyme disease screening
questionnaire would be clinically useful for both providers and patients. Three studies evaluated
such a screening tool, namely the Horowitz Multiple Systemic Infectious Disease Syndrome
(MSIDS) Questionnaire. The purpose was to see if the questionnaire could accurately distinguish
between Lyme patients and healthy individuals.
Methods: Study 1 examined the construct validity of the scale examining its factor structure
and reliability of the questionnaire among 537 individuals being treated for Lyme disease. Study
2 involved an online sample of 999 participants, who self-identified as either healthy (N=217) or
suffering from Lyme now (N=782) who completed the Horowitz MSIDS Questionnaire (HMQ)
along with an outdoor activity survey. We examined convergent validity among components of
the scale and evaluated discriminant validity with the Big Five personality characteristics. The
third study compared a sample of 236 patients with confirmed Lyme disease with an online
sample of 568 healthy individuals.
Results: Factor analysis results identified six underlying latent dimensions; four of these
overlapped with critical symptoms identified by Horowitz – neuropathy, cognitive dysfunction,
musculoskeletal pain, and fatigue. The HMQ showed acceptable levels of internal reliability
using Cronbach’s coefficient alpha and exhibited evidence of convergent and divergent validity.
Components of the HMQ correlated more highly with each other than with unrelated traits.
Discussion: The results consistently demonstrated that the HMQ accurately differentiated
those with Lyme disease from healthy individuals. Three migratory pain survey items (persistent
muscular pain, arthritic pain, and nerve pain/paresthesias) robustly identified individuals with
verified Lyme disease. The results support the use of the HMQ as a valid, efficient, and low-cost
screening tool for medical practitioners to decide if additional testing is warranted to distinguish
between Lyme disease and other illnesses.
Keywords: Lyme disease, Borrelia burgdorferi, Babesia, MSIDS, Multiple Systemic Infectious
Disease Syndrome, factor analysis, PTLDS, Post-Treatment Lyme Disease Syndrome