Table 4 Assessment of observed data from cohort studies with Bradford Hill criteria for assessing a potential causal relationship between psychological stress and symptom exacerbation
Exposure | Studies | Disease | Cohort size | Strength of association | Temporality | Coherence | Consistency | Biological gradient | Experiment | Plausibility | Criteria met |
|---|---|---|---|---|---|---|---|---|---|---|---|
Depression Depression Depression Depression Depression Depression Depression Depression Depression Depression Depression Depression Depression Depression Depression | Mardini 2004 North 1991 Mikocka-Walus 2008 Mittermaier 2004 Vidal De Lima 2012 Bitton 2007 Bitton 2003 Langhorst 2013 Levenstein 2000 Camara 2011 Gaines 2016 Mikocka-Walus 2016 Gracie 2018 Kochar 2018 Kochar 2018 | CD IBD IBD IBD CD CD UC UC UC CD CD IBD IBD CD UC | 18 32 127 60 50 87 60 75 62 468 2144 2007 405 2798 1516 | Strong = 1 Strong = 1 Weak = 0 Weak = 0 None = 0 Weak = 0 Weak = 0 Weak = 0 None = 0 Weak = 0 Strong = 1 Strong = 1 Weak = 0 Moderate = 1 Weak = 0 | 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 | N/A | 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 | N/A | N/A | 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 | 4 4 3 3 3 3 3 3 3 3 4 4 3 4 3 |
Perceived stress Perceived stress Perceived stress Perceived stress Perceived stress Perceived stress Perceived stress Perceived stress Perceived stress | Bernstein 2010 Duffy 1992 Mittermaier 2004 Bitton 2007 Bitton 2003 Langhorst 2013 Levenstein 2000 Camara 2011 Bernstein 2016 | IBD IBD IBD CD UC UC UC CD IBD | 552 123 60 87 60 75 62 468 487 | Moderate = 1 Moderate = 1 Weak = 0 Weak = 0 Weak = 0 None = 0 Strong = 1 Weak = 0 Strong = 1 | 1 1 1 1 1 1 1 1 1 | N/A | 1 1 1 1 1 1 1 1 1 | N/A | N/A | 1 1 1 1 1 1 1 1 1 | 4 4 3 3 3 3 4 3 4 |
Anxiety Anxiety Anxiety Anxiety Anxiety Anxiety Anxiety Anxiety Anxiety | Mardini 2004 Mikocka-Walus 2008 Mittermaier 2004 Vidal De Lima 2012 Bitton 2007 Bitton 2003 Camara 2011 Mikocka-Walus 2016 Gracie 2018 | CD IBD IBD CD CD UC CD IBD IBD | 18 127 60 50 87 60 468 2007 | Strong = 1 Weak = 0 Weak = 0 None = 0 Weak = 0 Weak = 0 Weak = 0 Strong = 1 Moderate = 1 | 1 1 1 1 1 1 1 1 1 | N/A | 1 1 1 1 1 1 1 1 1 | N/A | N/A | 1 1 1 1 1 1 1 1 1 | 4 3 3 3 3 3 3 4 4 |
Major life stress Major life stress Major life stress Major life stress | Bernstein 2010 Duffy 1992 Duffy 1991 Levenstein 2000 | IBD IBD IBD UC | 552 123 124 62 | Weak = 0 Moderate = 1 Moderate = 1 None = 0 | 1 1 1 1 | N/A | 1 1 1 1 | N/A | N/A | 1 1 1 1 | 3 4 4 3 |
Recent life events Recent life events Recent life events Recent life events | Mardini 2004 North 1991 Vidal 2006 Bitton 2003 | CD IBD IBD UC | 18 32 155 60 | Weak = 0 Moderate = 1 /strong = 1 None = 0 None = 0 | 1 1 1 1 1 | N/A | 1 1 1 1 1 | N/A | N/A | 1 1 1 1 1 | 3 4 4 3 3 |
Daily strains Daily strains | Duffy 1992 Bitton 2008 | IBD CD | 123 87 | Weak = 0 Weak = 0 | 1 1 | N/A | 1 1 | N/A | N/A | 1 1 | 3 3 |
Low + mood High − mood | Bernstein 2010 Bernstein 2010 | IBD IBD | 552 552 | Weak = 0 None = 0 | 1 1 | N/A | 1 | N/A | N/A | 1 | 3 3 |
Hopelessness | Mardini 2004 | CD | 18 | Strong = 1 | 1 | N/A | 1 | N/A | N/A | 1 | 4 |
Psychological distress | Bitton 2003 | UC | 60 | Weak = 0 | 1 | N/A | 1 | N/A | N/A | 1 | 3 |
Long-term stress | Langhorst 2013 | UC | 75 | None = 0 | 1 | N/A | 1 | N/A | N/A | 1 | 3 |