The Horowitz MSIDS Questionnaire (HMQ)
Answer the following questions as honestly as possible. Think about how you have been feeling over the previous month and how often you have been bothered by any of the following problems. Score the occurrence and frequency of each symptom on the following scale: never, sometimes, most of the time, all of the time or not applicable.
If you scored: Below 25 Not Likely to Have Tick-Borne illness
If you scored: 25-44 Possible Tick-borne Illness
If you scored: 45-62 Likely to have Tick-borne Illness
If you scored: Above 63 Highly Likely to have Tick-born Illness
Empirical Validation of the Horowitz Multiple Systemic Infectious Disease Syndrome Questionnaire for Suspected Lyme Disease
Citera, Freeman,& Horowitz (under Review at PLoS One)
Lyme disease is spreading worldwide, with multiple Borrelia species causing a broad range of clinical symptoms mimicking other illnesses. Serological laboratory tests for Lyme are known to be insensitive and unreliable, due to the bacteria’s ability to avoid immune recognition. A validated screening questionnaire would be clinically useful for both providers and patients. Three studies evaluated the Horowitz Multiple Systemic Infectious Disease Syndrome (MSIDS) Questionnaire (HMQ). Study 1, examined factor analysis and the psychometric properties of the questionnaire (reliability, construct, divergent and predictive validity) among 537 individuals being treated for Lyme disease. Study 2 involved an online sample of 1142 participants, who self-identified as either healthy (N=360) or suffering from Lyme now (N=782) and who completed the HMQ along with an outdoor activity survey. We examined convergent validity among the components of the scale and evaluated discriminant validity with the Big 5 personality characteristics. The third study compared the patient sample from Study 1 with an online sample of 637 healthy individuals. The purpose was to see if the questionnaire could accurately distinguish between Lyme patients and healthy individuals. Factor analysis results identified six underlying latent dimensions; four of these overlapped with critical symptoms identified by Horowitz—Neuropathy, Cognitive Dysfunction, Muscular/Skeletal Pain, and Fatigue. The HMQ showed acceptable levels of internal reliability using Cronbach’s Coefficient alpha. HMQ scores exhibited evidence of convergent and divergent validity. Components of the HMQ correlated more highly with each other than with unrelated traits. The results consistently demonstrated that the HMQ accurately differentiated those with Lyme disease from healthy individuals. The results support the use of the HMQ as a valid, efficient screening tool for medical practitioners and as an aid to individuals that may need to seek treatment.