title: Trajectories of multimorbidity: exploring patterns of multimorbidity in patients with more than ten chronic health problems in life course.
abstract: BACKGROUND
  Physicians are frequently confronted with complex health situations of patients, but knowledge of intensive forms of multimorbidity and their development during life is lacking. This study explores patterns and trajectories of chronic health problems of patients with multimorbidity particularly those with more than ten conditions and type and variety of organ systems involved in these patterns during life.
  
  
  METHODS
  Life time prevalence patterns of chronic health problems were determined in patients with illness trajectories accumulating more than ten chronic health problems during life as registered by general practitioners in the South of the Netherlands in the Registration Network Family Practices (RNH).
  
  
  RESULTS
  Overall 4,560 subjects (5%) were registered with more than ten chronic health problems during their life (MM11+), accounting for 61,653 (20%) of the 302,808 registered health problems in the population (N = 87,837 subjects). More than 30% accumulates 4 or more chronic health conditions (MM4-5: 4-5 conditions (N = 14,199; 16.2%); MM6-10: 6-10 conditions (N = 14,365; 16.4%). Gastro-intestinal, cardiovascular, locomotor, respiratory and metabolic conditions occur more frequently in the MM11+ patients than in the other patients, while the nature and variety of body systems involved in lifetime accumulation of chronic health problem clusters is both generic and specific. Regarding chronic conditions afflicting multiple sites throughout the body, the number of neoplasms seems low (N = 3,592; 5.8%), but 2,461 (49%) of the 4,560 subjects have registered at least one neoplasm condition during life. A similar pattern is noted for inflammation (N = 3,537, 78%), infection (N = 2,451, 54%) and injury (N = 3,401, 75%).
  
  
  CONCLUSIONS
  There are many challenges facing multimorbidity research, including the implementation of a longitudinal, life-time approach from a family practice perspective. The present study, although exploratory by nature, shows that both general and specific mechanisms characterize the development of multimorbidity trajectories. A small proportion of patients has a high number of chronic health problems (MM11+) and keeps adding health problems during life. However, GP's need to realise that more than one third of their patients accumulate four or more chronic health problems (MM4-5 and MM6-10) during life.
authors.affiliation: School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands. rein.vos@maastrichtuniversity.nl.
authors.forename: Rein
authors.initials: R
authors.lastname: Vos
authors.affiliation: Department of Family Medicine, School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands. marjan.vandenakker@maastrichtuniversity.nl.|Department of General Practice, Catholic University Leuven, Leuven, Belgium. marjan.vandenakker@maastrichtuniversity.nl.
authors.forename: Marjan
authors.initials: M
authors.lastname: van den Akker
authors.affiliation: Department of Family Medicine, School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands. jos.boesten@maastrichtuniversity.nl.
authors.forename: Jos
authors.initials: J
authors.lastname: Boesten
authors.affiliation: Department of Family Medicine, School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands. c.robertson@maastrichtuniversity.nl.
authors.forename: Caroline
authors.initials: C
authors.lastname: Robertson
authors.affiliation: Department of Family Medicine, School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands. job.metsemakers@maastrichtuniversity.nl.
authors.forename: Job
authors.initials: J
authors.lastname: Metsemakers
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002908:Chronic Disease / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D020233:Gait Disorders, Neurologic / Q000453:epidemiology; D058006:General Practice; D058005:General Practitioners; D006304:Health Status; D006801:Humans; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology; D009426:Netherlands / Q000453:epidemiology; D010819:Physician's Role; D015995:Prevalence; D012140:Respiratory Tract Diseases / Q000453:epidemiology