title: Correlation between pain, disability, and quality of life in patients with common low back pain.
abstract: METHODS
  Correlation among previously validated questionnaires.
  
  
  OBJECTIVE
  To determine the correlation between pain, disability, and quality of life in patients with low back pain.
  
  
  BACKGROUND
  The Visual Analogue Scale (VAS), and the Roland-Morris (RMQ), Oswestry (OQ), and EuroQol (EQ) Questionnaires are validated instruments to assess pain, low back pain-related disability, and quality of life.
  
  
  METHODS
  The study was done in the primary care setting, in Mallorca, with 195 patients who visited their physician for LBP. Individuals were given the VAS, RMQ, OQ, and EQ on their first visit and 14 days later.
  
  
  RESULTS
  Median duration of pain when entering the study was 10 days (P25,P75: 3, 40). On day 1, simple correlation was r = 0.347 between VAS and RMQ, r = -0.422 between VAS and EQ, and r = -0.442 between RMQ and EQ. On day 15, simple correlation was r = 0.570 between VAS and RMQ, r = -0.672 between VAS and EQ, and r = -0.637 between RMQ and EQ. Multiple linear regression models showed that, on day 1, the VAS score explains 12% of the RMQ score and the VAS and RMQ scores explain 27% of the EQ score. On day 15, the VAS score explains 33% of the RMQ score, and the VAS and RMQ scores explain 58% of the EQ score. On day 1, a 10% increase in VAS worsens disability by 3.3% and quality of life by 2.65%. On day 15, a 10% increase in VAS worsens disability by 4.99% and quality of life by 3.80%. Prestudy duration of pain had no influence on any model. All these correlation coefficients and models are significant at the P < 0.001 level. The OQ had lower correlation values with the other three scales, and only two of them were significant.
  
  
  CONCLUSIONS
  Clinically relevant improvements in pain may lead to almost unnoticeable changes in disability and quality of life. Therefore, these variables should be assessed separately when evaluating the effect of any form of treatment for low back pain. The influence of pain and disability on quality of life progresses while they last, and doubles in 14 days. In acute and subacute patients, this increase is not dependent on the previous duration of pain.
authors.affiliation: Departamento Científico, Fundación Kovacs, Palma de Mallorca and Madrid, Spain. kovacs@kovacs.org
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Kovacs
authors.forename: Víctor
authors.initials: V
authors.lastname: Abraira
authors.forename: Javier
authors.initials: J
authors.lastname: Zamora
authors.forename: María
authors.initials: M
authors.lastname: Teresa Gil del Real
authors.forename: Joan
authors.initials: J
authors.lastname: Llobera
authors.forename: Carmen
authors.initials: C
authors.lastname: Fernández
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Bauza
authors.forename: Kunibert
authors.initials: K
authors.lastname: Bauza
authors.forename: Josep
authors.initials: J
authors.lastname: Coll
authors.forename: María
authors.initials: M
authors.lastname: Cuadri
authors.forename: Elena
authors.initials: E
authors.lastname: Duro
authors.forename: Juan
authors.initials: J
authors.lastname: Gili
authors.forename: Mario
authors.initials: M
authors.lastname: Gestoso
authors.forename: Marina
authors.initials: M
authors.lastname: Gómez
authors.forename: Juana
authors.initials: J
authors.lastname: González
authors.forename: Patricia
authors.initials: P
authors.lastname: Ibañez
authors.forename: Antoni
authors.initials: A
authors.lastname: Jover
authors.forename: Pablo
authors.initials: P
authors.lastname: Lázaro
authors.forename: Miguel
authors.initials: M
authors.lastname: Llinás
authors.forename: Catalina
authors.initials: C
authors.lastname: Mateu
authors.forename: Nicole
authors.initials: N
authors.lastname: Mufraggi
authors.forename: Alfonso
authors.initials: A
authors.lastname: Muriel
authors.forename: Carmen
authors.initials: C
authors.lastname: Nicolau
authors.forename: María Arrate
authors.initials: MA
authors.lastname: Olivera
authors.forename: Patricia
authors.initials: P
authors.lastname: Pascual
authors.forename: Lourdes
authors.initials: L
authors.lastname: Perelló
authors.forename: Francisco
authors.initials: F
authors.lastname: Pozo
authors.forename: Teresa
authors.initials: T
authors.lastname: Revuelta
authors.forename: Vicente
authors.initials: V
authors.lastname: Reyes
authors.forename: Sebestián
authors.initials: S
authors.lastname: Ribot
authors.forename: Jaime
authors.initials: J
authors.lastname: Ripoll
authors.forename: Juana
authors.initials: J
authors.lastname: Ripoll
authors.forename: Elena
authors.initials: E
authors.lastname: Rodríguez
mesh_terms: D004185:Disability Evaluation; D005260:Female; D006304:Health Status; D006801:Humans; D016014:Linear Models; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011788:Quality of Life; D018434:Sickness Impact Profile; D013030:Spain / Q000453:epidemiology; D013223:Statistics as Topic; D011795:Surveys and Questionnaires