How much change is enough? Evidence from a longitudinal study on depression in UK primary care

Daphne Kounali; Katherine S. Button; Gemma Lewis; Simon Gilbody; David Kessler; Ricardo Araya; Larisa Duffy; Paul Lanham; Tim J. Peters; Nicola Wiles; Glyn Lewis

doi:10.1017/S0033291720003700

How much change is enough? Evidence from a longitudinal study on depression in UK primary care

Daphne Kounali^*, Katherine S. Button, Gemma Lewis, Simon Gilbody, David Kessler, Ricardo Araya, Larisa Duffy, Paul Lanham, Tim J. Peters, Nicola Wiles, Glyn Lewis

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

76 Citations (Scopus)

Abstract

Background The Patient Health Questionnaire (PHQ-9), the Beck Depression Inventory (BDI-II) and the Generalised Anxiety Disorder Assessment (GAD-7) are widely used in the evaluation of interventions for depression and anxiety. The smallest reduction in depressive symptoms that matter to patients is known as the Minimum Clinically Important Difference (MCID). Little empirical study of the MCID for these scales exists. Methods A prospective cohort of 400 patients in UK primary care were interviewed on four occasions, 2 weeks apart. At each time point, participants completed all three questionnaires and a 'global rating of change' scale (GRS). MCID estimation relied on estimated changes in symptoms according to reported improvement on the GRS scale, stratified by baseline severity on the Clinical Interview Schedule (CIS-R). Results For moderate baseline severity, those who reported improvement on the GRS had a reduction of 21% (95% confidence interval (CI) -26.7 to -14.9) on the PHQ-9; 23% (95% CI -27.8 to -18.0) on the BDI-II and 26.8% (95% CI -33.5 to -20.1) on the GAD-7. The corresponding threshold scores below which participants were more likely to report improvement were -1.7, -3.5 and -1.5 points on the PHQ-9, BDI-II and GAD-7, respectively. Patients with milder symptoms require much larger reductions as percentage of their baseline to endorse improvement. Conclusions An MCID representing 20% reduction of scores in these scales, is a useful guide for patients with moderately severe symptoms. If treatment had the same effect on patients irrespective of baseline severity, those with low symptoms are unlikely to notice a benefit. Funding Funding. National Institute for Health Research.

Original language	English
Journal	Psychological Medicine
DOIs	https://doi.org/10.1017/S0033291720003700
Publication status	Accepted/In press - 2020

Keywords

Baseline severity depression
BDI-II
beta-regression
depression
GAD-7
minimal clinically important difference
PHQ-9
primary care

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10.1017/S0033291720003700

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@article{3b1e1da0eeed46519d7ebbf36dfc2f7c,

title = "How much change is enough? Evidence from a longitudinal study on depression in UK primary care",

abstract = "Background The Patient Health Questionnaire (PHQ-9), the Beck Depression Inventory (BDI-II) and the Generalised Anxiety Disorder Assessment (GAD-7) are widely used in the evaluation of interventions for depression and anxiety. The smallest reduction in depressive symptoms that matter to patients is known as the Minimum Clinically Important Difference (MCID). Little empirical study of the MCID for these scales exists. Methods A prospective cohort of 400 patients in UK primary care were interviewed on four occasions, 2 weeks apart. At each time point, participants completed all three questionnaires and a 'global rating of change' scale (GRS). MCID estimation relied on estimated changes in symptoms according to reported improvement on the GRS scale, stratified by baseline severity on the Clinical Interview Schedule (CIS-R). Results For moderate baseline severity, those who reported improvement on the GRS had a reduction of 21% (95% confidence interval (CI) -26.7 to -14.9) on the PHQ-9; 23% (95% CI -27.8 to -18.0) on the BDI-II and 26.8% (95% CI -33.5 to -20.1) on the GAD-7. The corresponding threshold scores below which participants were more likely to report improvement were -1.7, -3.5 and -1.5 points on the PHQ-9, BDI-II and GAD-7, respectively. Patients with milder symptoms require much larger reductions as percentage of their baseline to endorse improvement. Conclusions An MCID representing 20% reduction of scores in these scales, is a useful guide for patients with moderately severe symptoms. If treatment had the same effect on patients irrespective of baseline severity, those with low symptoms are unlikely to notice a benefit. Funding Funding. National Institute for Health Research.",

keywords = "Baseline severity depression, BDI-II, beta-regression, depression, GAD-7, minimal clinically important difference, PHQ-9, primary care",

author = "Daphne Kounali and Button, {Katherine S.} and Gemma Lewis and Simon Gilbody and David Kessler and Ricardo Araya and Larisa Duffy and Paul Lanham and Peters, {Tim J.} and Nicola Wiles and Glyn Lewis",

year = "2020",

doi = "10.1017/S0033291720003700",

language = "English",

journal = "Psychological Medicine",

issn = "0033-2917",

publisher = "Cambridge University Press",

}

TY - JOUR

T1 - How much change is enough? Evidence from a longitudinal study on depression in UK primary care

AU - Kounali, Daphne

AU - Button, Katherine S.

AU - Lewis, Gemma

AU - Gilbody, Simon

AU - Kessler, David

AU - Araya, Ricardo

AU - Duffy, Larisa

AU - Lanham, Paul

AU - Peters, Tim J.

AU - Wiles, Nicola

AU - Lewis, Glyn

PY - 2020

Y1 - 2020

N2 - Background The Patient Health Questionnaire (PHQ-9), the Beck Depression Inventory (BDI-II) and the Generalised Anxiety Disorder Assessment (GAD-7) are widely used in the evaluation of interventions for depression and anxiety. The smallest reduction in depressive symptoms that matter to patients is known as the Minimum Clinically Important Difference (MCID). Little empirical study of the MCID for these scales exists. Methods A prospective cohort of 400 patients in UK primary care were interviewed on four occasions, 2 weeks apart. At each time point, participants completed all three questionnaires and a 'global rating of change' scale (GRS). MCID estimation relied on estimated changes in symptoms according to reported improvement on the GRS scale, stratified by baseline severity on the Clinical Interview Schedule (CIS-R). Results For moderate baseline severity, those who reported improvement on the GRS had a reduction of 21% (95% confidence interval (CI) -26.7 to -14.9) on the PHQ-9; 23% (95% CI -27.8 to -18.0) on the BDI-II and 26.8% (95% CI -33.5 to -20.1) on the GAD-7. The corresponding threshold scores below which participants were more likely to report improvement were -1.7, -3.5 and -1.5 points on the PHQ-9, BDI-II and GAD-7, respectively. Patients with milder symptoms require much larger reductions as percentage of their baseline to endorse improvement. Conclusions An MCID representing 20% reduction of scores in these scales, is a useful guide for patients with moderately severe symptoms. If treatment had the same effect on patients irrespective of baseline severity, those with low symptoms are unlikely to notice a benefit. Funding Funding. National Institute for Health Research.

AB - Background The Patient Health Questionnaire (PHQ-9), the Beck Depression Inventory (BDI-II) and the Generalised Anxiety Disorder Assessment (GAD-7) are widely used in the evaluation of interventions for depression and anxiety. The smallest reduction in depressive symptoms that matter to patients is known as the Minimum Clinically Important Difference (MCID). Little empirical study of the MCID for these scales exists. Methods A prospective cohort of 400 patients in UK primary care were interviewed on four occasions, 2 weeks apart. At each time point, participants completed all three questionnaires and a 'global rating of change' scale (GRS). MCID estimation relied on estimated changes in symptoms according to reported improvement on the GRS scale, stratified by baseline severity on the Clinical Interview Schedule (CIS-R). Results For moderate baseline severity, those who reported improvement on the GRS had a reduction of 21% (95% confidence interval (CI) -26.7 to -14.9) on the PHQ-9; 23% (95% CI -27.8 to -18.0) on the BDI-II and 26.8% (95% CI -33.5 to -20.1) on the GAD-7. The corresponding threshold scores below which participants were more likely to report improvement were -1.7, -3.5 and -1.5 points on the PHQ-9, BDI-II and GAD-7, respectively. Patients with milder symptoms require much larger reductions as percentage of their baseline to endorse improvement. Conclusions An MCID representing 20% reduction of scores in these scales, is a useful guide for patients with moderately severe symptoms. If treatment had the same effect on patients irrespective of baseline severity, those with low symptoms are unlikely to notice a benefit. Funding Funding. National Institute for Health Research.

KW - Baseline severity depression

KW - BDI-II

KW - beta-regression

KW - depression

KW - GAD-7

KW - minimal clinically important difference

KW - PHQ-9

KW - primary care

UR - http://www.scopus.com/inward/record.url?scp=85095763543&partnerID=8YFLogxK

U2 - 10.1017/S0033291720003700

DO - 10.1017/S0033291720003700

M3 - Article

AN - SCOPUS:85095763543

SN - 0033-2917

JO - Psychological Medicine

JF - Psychological Medicine

ER -

How much change is enough? Evidence from a longitudinal study on depression in UK primary care

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Keywords

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