title: Distinct trajectories of multimorbidity in primary care were identified using latent class growth analysis.
abstract: OBJECTIVE
  To investigate the use of latent class growth analysis (LCGA) in understanding onset and changes in multimorbidity over time in older adults.
  
  
  METHODS
  This study used primary care consultations for 42 consensus-defined chronic morbidities over 3 years (2003-2005) by 24,615 people aged >50 years at 10 UK general practices, which contribute to the Consultations in Primary Care Archive database. Distinct groups of people who had similar progression of multimorbidity over time were identified using LCGA. These derived trajectories were tested in another primary care consultation data set with linked self-reported health status.
  
  
  RESULTS
  Five clusters of people representing different trajectories were identified: those who had no recorded chronic problems (40%), those who developed a first chronic morbidity over 3 years (10%), a developing multimorbidity group (37%), a group with increasing number of chronic morbidities (12%), and a multi-chronic group with many chronic morbidities (1%). These trajectories were also identified using another consultation database and associated with self-reported physical and mental health.
  
  
  CONCLUSIONS
  There are distinct trajectories in the development of multimorbidity in primary care populations, which are associated with poor health. Future research needs to incorporate such trajectories when assessing progression of disease and deterioration of health.
authors: Arthritis Research UK Primary Care Centre, Keele University, the Institute of Primary Care and Health Sciences, Keele, Staffordshire ST5 5BG, United Kingdom; Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom. Electronic address: Victoria.strauss@csm.ox.ac.uk.
authors: Vicky Y
authors: VY
authors: Strauss
authors: The Health Service Research Unit, the Institute for Science & Technology in Medicine, Innovation Centre 1, Keele University, Staffordshire ST5 5BG, United Kingdom.
authors: Peter W
authors: PW
authors: Jones
authors: Arthritis Research UK Primary Care Centre, Keele University, the Institute of Primary Care and Health Sciences, Keele, Staffordshire ST5 5BG, United Kingdom; The Health Service Research Unit, the Institute for Science & Technology in Medicine, Innovation Centre 1, Keele University, Staffordshire ST5 5BG, United Kingdom.
authors: Umesh T
authors: UT
authors: Kadam
authors: Arthritis Research UK Primary Care Centre, Keele University, the Institute of Primary Care and Health Sciences, Keele, Staffordshire ST5 5BG, United Kingdom.
authors: Kelvin P
authors: KP
authors: Jordan
mesh_terms: D000368:Aged; D002908:Chronic Disease / Q000453:epidemiology*; D016000:Cluster Analysis; D015897:Comorbidity / Q000639:trends*; D059026:Diagnostic Self Evaluation; D005260:Female; D058006:General Practice; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D011320:Primary Health Care / Q000706:statistics & numerical data*; D006113:United Kingdom / Q000453:epidemiology
keywords: Comorbidity; Latent class growth analysis; Longitudinal studies; Medical records; Multimorbidity; Primary health care