title: Double trouble: the impact of multimorbidity and deprivation on preference-weighted health related quality of life a cross sectional analysis of the Scottish Health Survey.
abstract: OBJECTIVE
  To investigate the association between multimorbidity and Preference_Weighted Health Related Quality of Life (PW_HRQoL), a score that combines physical and mental functioning, and how this varies by socioeconomic deprivation and age.
  
  
  METHODS
  The Scottish Health Survey (SHeS) is a cross-sectional representative survey of the general population which included the SF-12, a survey of HRQoL, for individuals 20 years and over.
  
  
  METHODS
  For 7,054 participants we generated PW_HRQoL scores by running SF-12 responses through the SF-6D algorithm. The resulting scores ranged from 0.29 (worst health) to 1 (perfect health). Using ordinary least squares, we first investigated associations between scores and increasing counts of longstanding conditions, and then repeated for multimorbidity (2+ conditions). Estimates were made for the general population and quintiles of socioeconomic deprivation. For multimorbidity, the analyses were repeated stratifying the population by age group (20-44, 45-64, 65+).
  
  
  RESULTS
  45% of participants reported a longstanding condition and 18% reported multimorbidity. The presence of 1, 2, or 3+ longstanding conditions were associated with average reductions in PW_HRQoL scores of 0.081, 0.151 and 0.212 respectively. Reduction in scores associated with multimorbidity was 33% greater in the most deprived quintile compared to the least deprived quintile, with the biggest difference (80%) in the 20-44 age groups. There were no significant gender differences.
  
  
  CONCLUSIONS
  PW_HRQoL decreases markedly with multimorbidity, and is exacerbated by higher deprivation and younger age. There is a need to prioritise interventions to improve the HRQoL for (especially younger) adults with multimorbidity in deprived areas. BOX 1: What Is Known?Prevalence and premature onset of multimorbidity increases as socioeconomic position worsens. Previous studies have investigated the effect of multimorbidity on Health Related Quality of Life (HRQoL) on separate physical and mental health states. There is limited data on how HRQoL falls as the number of conditions increase, and how estimates vary across the general population.Leaving physical and mental health as separate categories can inhibit assessment of overall HRQoL. The use of a Preference_Weighted Health Related Quality of Life (PW_HRQoL) score provides a single summary measure of overall health, by weighting mental and physical states by their perceived importance as part of overall HRQoL. The use of a single score enables a simple and consistent assessment of the impact of conditions and how this varies across the population. Economists term PW_HRQoL scores health utilities.What this study adds?This is the first study to estimate how the impact of multimorbidity on PW_HRQoL scores varies by age group and socioeconomic deprivation. Multimorbidity has a substantial negative impact on HRQoL which is most severe in areas of deprivation, especially in younger adults.Measuring the burden of multimorbidity using PW_HRQoL provides consistency with how economists measure HRQoL; changes in which can be used in economic evaluation to assess the cost effectiveness of interventions.
authors: Health Economics and HTA, Institute of Health & Wellbeing, University of Glasgow, 1 Lilybank Gardens, Glasgow G12 8RZ, UK. Kenny.Lawson@glasgow.ac.uk
authors: Kenny D
authors: KD
authors: Lawson
authors: Stewart W
authors: SW
authors: Mercer
authors: Sally
authors: S
authors: Wyke
authors: Eleanor
authors: E
authors: Grieve
authors: Bruce
authors: B
authors: Guthrie
authors: Graham C M
authors: GC
authors: Watt
authors: Elisabeth A E
authors: EA
authors: Fenwick
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D054624:Health Status Disparities; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012606:Scotland / Q000453:epidemiology; D012959:Socioeconomic Factors; D055815:Young Adult
references: Qual Life Res. 2006 Feb;15(1):83-91
references: 16411033
references: Cochrane Database Syst Rev. 2012 Apr 18;(4):CD006560
references: 22513941
references: Lancet. 2012 Jul 7;380(9836):37-43
references: 22579043
references: Ann Fam Med. 2012 Mar-Apr;10(2):142-51
references: 22412006
references: Ann Fam Med. 2007 Nov-Dec;5(6):503-10
references: 18025487
references: BMJ. 2012 Jun 13;344:e3526
references: 22695898
references: J Comorb. 2011 Dec 27;1:4-7
references: 29090130
references: Can Fam Physician. 2005 Feb;51:244-5
references: 16926936
references: Br J Gen Pract. 2012 Apr;62(597):e297-307
references: 22520918
references: Chronic Illn. 2011 Mar;7(1):45-59
references: 20974642
references: Med Care. 2004 Sep;42(9):851-9
references: 15319610
references: Health Qual Life Outcomes. 2003 Oct 16;1:54
references: 14613568
references: Br J Gen Pract. 2009 Nov;59(568):e353-8
references: 19656444
references: Qual Life Res. 2005 Dec;14(10):2187-96
references: 16328899
references: Health Qual Life Outcomes. 2007 Aug 06;5:52
references: 17683600
references: Health Qual Life Outcomes. 2004 Sep 20;2:51
references: 15380021