title: Reliability and validity of the Polish version of the Core Outcome Measures Index for the neck.
abstract: OBJECTIVE
  Patient reported outcome measures play an increasingly important role in the outcomes research. The Core Outcome Measures Index (COMI) is a short, multidimensional instrument initially developed for the use by patients with low back pain. This study is an evaluation of a Polish version of COMI adapted for neck pain.
  
  
  METHODS
  One hundred twenty-three patients complaining of neck pain were enrolled. All of them completed a questionnaire booklet containing COMI-neck, Neck Disability Index and Likert-type questions regarding the frequency of use of pain medications and pain frequency. Ninety-eight patients returned the retest questionnaire. Data quality was also assessed. Assessment of psychometric properties included examination of data quality, construct validity, test-retest reliability and factor analysis.
  
  
  RESULTS
  The quality of data was good with no missing answers and a little floor effect. Exploratory factor analysis revealed a single-factor structure. Reliability expressed as intraclass correlation coefficient was 0.88 (95% CI 0.84-0.92) for the overall COMI score and was generally good for most of individual core items. The minimum detectable change (MDC95%) was 1.97.
  
  
  CONCLUSIONS
  This version of the COMI-neck is a valid and reliable instrument, with good psychometric properties. It can be recommended for Polish-speaking patients.
authors.affiliation: Department of Neurosurgery, Specialist Medical Center, Polanica-Zdroj, Poland, gmiekisiak@gmail.com.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Miekisiak
authors.forename: Mariusz
authors.initials: M
authors.lastname: Banach
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Kiwic
authors.forename: Lukasz
authors.initials: L
authors.lastname: Kubaszewski
authors.forename: Jacek
authors.initials: J
authors.lastname: Kaczmarczyk
authors.forename: Adam
authors.initials: A
authors.lastname: Sulewski
authors.forename: Wojciech
authors.initials: W
authors.lastname: Kloc
authors.forename: Witold
authors.initials: W
authors.lastname: Libionka
authors.forename: Dariusz
authors.initials: D
authors.lastname: Latka
authors.forename: Marta
authors.initials: M
authors.lastname: Kollataj
authors.forename: Rafal
authors.initials: R
authors.lastname: Zaluski
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis*; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010147:Pain Measurement / Q000379:methods*; D011044:Poland; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D057566:Self Report; D011795:Surveys and Questionnaires; D055815:Young Adult