Efficacy and Safety of 10-Week or Shorter vs 12-Week or Longer Injection Intervals of Botulinum Toxin

Our project has the following aims:

Aim 1: to determine if any difference exists in safety or efficacy between patients receiving injections of botulinum toxin at 10-week or shorter intervals as compared to patients receiving injections at 12-week or longer intervals.

Aim 2: to determine if patients who have expressed a preference for injections at 10 week or shorter intervals but whose insurance carriers have mandated a 12-week interval have worse health related quality of life as compared to patients who are receiving injections at 10-week or shorter intervals.

This project consists of two analyses, each designed to accomplish aims 1 and 2. For both aims, we will invite consecutive patients who meet entry criteria to participate who are followed in the botulinum toxin injection clinics of the University of Texas Southwestern Medical Center movement disorders faculty. Participants who consent to data collection by participating in an email-administered survey of quality of life will have their medical records reviewed by an investigator for abstraction of clinical data (to include dose, injection site, injection interval, side effects, demographics, and diagnoses). Additionally, patients will fill out two or more survey instruments on the date of their enrollment visit following their botulinum toxin injection visit. The survey instruments completed will be 1) the SF-36 health questionnaire and 2) a disease-specific HRQoL survey chosen to be applicable to the specific condition for which that subject is receiving botulinum toxin injections. Patients receiving injections for multiple conditions will receive surveys for each condition for which they are receiving treatment. The disease specific scales to be used selectively depending on the patient's specific condition include:

• Blepharospasm disability index
• Craniocervical dystonia questionnaire (CDQ-24)
• Arm dystonia disability scale (ADDS)
• Hemifacial spasm scale (HSF-7)
• Oromandibular dystonia questionnaire (OMDQ-25)
• Spasticity scale (SQoL-6D)

For analysis, patients will be segregated into two groups (10-week or shorter inter-injection interval and 12 week or longer inter-injection interval) on the basis of time elapsed between the most recent botulinum toxin treatments. Clinical and survey data will be analyzed to determine if differences exist between the two groups.

Inclusion criteria

Aim 1:

• Patient provides responses to an internet based survey which includes consent to participate
• Patient has been diagnosed with one or more of the conditions for which a HRQoL scale exists and will be employed in this study
• Patient has received at least 2 prior injections with botulinum toxin for that condition by one of the study investigators
• Both of the two most recent intervals between injections are either a) 10-weeks or less or b) 12-weeks or more

Aim 2:

• Patient provides responses to an internet based survey which includes consent to participate
• Patient has been diagnosed with one or more of the conditions for which a HRQoL scale exists and will be employed in this study
• Patient has received at least 2 prior injections with botulinum toxin for that condition by one of the study investigators
• Both of the two most recent intervals between injections are either a) 10-weeks or less or b) 12-weeks or more
• If receiving injections at 12-weeks or more, notes must have previously indicated that patient needs an injection interval of 10-weeks or less
• If receiving injections at 12-weeks or more, the reason must be that the insurance carrier covering that patient's medical costs refused to allow a 10-week or less injection frequency

Exclusion criteria

For both Aims 1 and 2:

• Patient is unwilling to consent to study procedures (refuses to fill out surveys)
• Patient has variable injection frequencies such that the two most recent injections do not both meet criteria of being 10-weeks or less in frequency or 12-weeks or more in frequency
• Patient has a diagnosis of and is being treated for a condition for which a HRQoL scale does not exist
• Patient has insufficient chart documentation to characterize demographics, diagnosis, toxin selected, dose used, and injection frequency employed