title: Recommendations for observational studies of comorbidity in multiple sclerosis.
abstract: OBJECTIVE
  To reach consensus about the most relevant comorbidities to study in multiple sclerosis (MS) with respect to incidence, prevalence, and effect on outcomes; review datasets that may support studies of comorbidity in MS; and identify MS outcomes that should be prioritized in such studies.
  
  
  METHODS
  We held an international workshop to meet these objectives, informed by a systematic review of the incidence and prevalence of comorbidity in MS, and an international survey regarding research priorities for comorbidity.
  
  
  RESULTS
  We recommend establishing age- and sex-specific incidence and prevalence estimates for 5 comorbidities (depression, anxiety, hypertension, hyperlipidemia, and diabetes); evaluating the effect of 7 comorbidities (depression, anxiety, hypertension, diabetes, hyperlipidemia, chronic lung disease, and autoimmune diseases) on disability, quality of life, brain atrophy and other imaging parameters, health care utilization, employment, and mortality, including age, sex, race/ethnicity, socioeconomic status, and disease duration as potential confounders; harmonizing study designs across jurisdictions; and conducting such studies worldwide. Ultimately, clinical trials of treating comorbidity in MS are needed.
  
  
  CONCLUSIONS
  Our recommendations will help address knowledge gaps regarding the incidence, prevalence, and effect of comorbidity on outcomes in MS.
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH. rmarrie@hsc.mb.ca.
authors: Ruth Ann
authors: RA
authors: Marrie
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Aaron
authors: A
authors: Miller
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Maria Pia
authors: MP
authors: Sormani
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Alan
authors: A
authors: Thompson
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Emmanuelle
authors: E
authors: Waubant
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Maria
authors: M
authors: Trojano
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Paul
authors: P
authors: O'Connor
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Kirsten
authors: K
authors: Fiest
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Nadia
authors: N
authors: Reider
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Stephen
authors: S
authors: Reingold
authors: From the Departments of Internal Medicine (R.A.M., K.F.) and Community Health Sciences (R.A.M., N.R.), University of Manitoba, Winnipeg, Canada; Icahn School of Medicine at Mount Sinai (A.M.), New York, NY; Biostatistic Unit, Department of Health Sciences (M.P.S.), University of Genova, Italy; Faculty of Brain Sciences (A.T.), University College London, UK; University of California San Francisco (E.W.); Department of Basic Medical Sciences, Neurosciences and Sense Organs (M.T.), University of Bari, Italy; St. Michael's Hospital (P.O.), Toronto, Canada; Scientific and Clinical Review Associates, LLC (S.R.), Salisbury, CT; and Mellen Center for MS Treatment and Research (J.A.C.), Cleveland Clinic, OH.
authors: Jeffrey A
authors: JA
authors: Cohen
mesh_terms: D015897:Comorbidity; D006801:Humans; D009103:Multiple Sclerosis / Q000150:complications / Q000453:epidemiology* / Q000628:therapy*; D064887:Observational Studies as Topic / Q000379:methods*; D012107:Research Design