How much change is enough? Evidence from a longitudinal study on depression in UK primary care
Open accessAbstract
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.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Clinical response was defined as either a ≥50% reduction from Baseline or an absolute decrease from Baseline of at least the instrument's minimum clinically important difference (MCID; 5 points for PHQ-9; 10 points for PCL-5 total; 4 points for GAD-7), whichever criterion was met.
“clinical response was defined as either a ≥ 50% reduction from Baseline or an absolute decrease from Baseline of at least the instrument's minimum clinically important difference (MciD; 5 points for PhQ-9; 10 points for Pcl-5 total; 4 points for GaD-7), whichever criterion was met (Bauer-staeb et al. 2021;Kounali et al. 2022;löwe et al. 2004)”
From Feasibility, tolerability, and preliminary effectiveness of an accelerated bilateral intermittent theta-burst stimulation protocol in adults with posttraumatic stress disorder and comorbid depressive disorder following mild traumatic brain injury (2026) · cites this paper as Kounali et al. 2022
The Results (ROC analysis, Table 5; page unavailable) give improvement thresholds of about 2 points for PHQ-9 and 1–2 points for GAD-7, rather than the claimed MCIDs of 5 and 4 points. The Discussion (Implications; page unavailable) says roughly 20% change corresponded to an MCID at moderate and higher severity, not a general 50% response threshold. The paper does not assess PCL-5. (LLM, conf=0.87)
Checked by a reasoning model — may be wrong.
Experimental — accuracy not yet measuredA reduction of 20% on the General Anxiety Disorder-7 is considered to be a minimum clinically important difference.
“(a reduction of 20 % on this scale is considered to be a minimum clinically important difference [16])”
From The clinical and cost effectiveness of internet-delivered self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS): Study protocol for a randomised controlled trial with ethnically diverse family carers (2024) · cites this paper as [16]
The Discussion (Implications) says roughly a 20% GAD-7 reduction corresponded to an MCID at moderate and higher baseline severity. The citing sentence omits that qualification; the paper says patients with lower baseline severity needed larger percentage reductions. (LLM, conf=0.88)
Experimental — accuracy not yet measuredA reduction of 20% on the GAD7 is considered to be a minimum clinically important difference.
“A reduction of 20 % on GAD7 is considered to be a minimum clinically important difference [16].”
From The clinical and cost effectiveness of internet-delivered self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS): Study protocol for a randomised controlled trial with ethnically diverse family carers (2024) · cites this paper as [16]
The Discussion (Implications) says that roughly a 20% GAD-7 change corresponded to an MCID at moderate and higher baseline severities, but not at lower severities. The Abstract (Conclusions) likewise calls 20% a useful guide for patients with moderately severe symptoms. The citing sentence omits that severity qualification and presents 20% as a general GAD-7 threshold. (LLM, conf=0.88)
Experimental — accuracy not yet measured
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
A Brief Measure for Assessing Generalized Anxiety Disorder: The GAD-7
Spitzer, R. L., Kroenke, K., Williams, J. B. W., & Löwe, B. (2006) · Archives of Internal Medicine · doi:10.1001/archinte.166.10.1092 · Cited by 31,765 · see citing works
Comparison of Beck Depression Inventories -IA and -II in psychiatric outpatients
Beck, A. T., Steer, R. A., Ball, R., & Ranieri, W. F. (1996) · Journal of Personality Assessment · doi:10.1207/s15327752jpa6703_13 · Cited by 5,965 · see citing works
The PHQ-9: A New Depression Diagnostic and Severity Measure
Kroenke, K., & Spitzer, R. L. (2002) · Psychiatric Annals · doi:10.3928/0048-5713-20020901-06 · Cited by 5,898 · see citing works
Lewis, G., Pelosi, A. J., Araya, R., & Dunn, G. (1992) · Psychological Medicine · doi:10.1017/s0033291700030415 · Cited by 1,487 · see citing works
Self-citationButton, K. S., Kounali, D., Thomas, L., Wiles, N. J., Peters, T. J., Welton, N. J., Ades, A. E., & Lewis, G. (2015) · Psychological Medicine · doi:10.1017/s0033291715001270 · Cited by 332 · see citing works
Self-citationLeucht, S., Fennema, H., Engel, R., Kaspers–Janssen, M., Lepping, P., & Szegedi, A. (2013) · Journal of Affective Disorders · doi:10.1016/j.jad.2012.12.001 · Cited by 211 · see citing works
Lewis, G., Duffy, L., Ades, A., Amos, R., Araya, R., Brabyn, S., Button, K. S., Churchill, R., Derrick, C., Dowrick, C., et al. (2019) · The Lancet Psychiatry · doi:10.1016/s2215-0366(19)30366-9 · Cited by 120 · see citing works
Self-citationRobinson, J., Khan, N., Fusco, L., Malpass, A., Lewis, G., & Dowrick, C. (2017) · BMJ Open · doi:10.1136/bmjopen-2016-014519 · Cited by 39 · see citing works
Self-citationHobbs, C., Lewis, G., Dowrick, C., Kounali, D., Peters, T. J., & Lewis, G. (2021) · Psychological Medicine · doi:10.1017/s0033291719003878 · Cited by 35 · see citing works
Self-citation
Flagged first, then by citations
Research works printed but not linked: 14
- Fischer, D., Stewart, A. L., Bloch, D. A., Lorig, K., Laurent, D. and Holman, H. (1999). Capturing the patient's view of change as a clinical outcome measure. Journal of the American Medical Association, 282(12), 1157– 1162. doi: 10.1001/jama.282.12.1157. 10501119 · DOI
- Hinman, R. S., McCrory, P., Pirotta, M., Relf, I., Forbes, A., Crossley, K. M., …, Bennell, K. L. (2014). Acupuncture for chronic knee pain: A randomized clinical trial. Journal of the American Medical Association, 312(13), 1313– 1322. doi: 10.1001/jama.2014.12660. 25268438 · DOI
- Kamper, S. J., Maher, C. G. and Mackay, G. (2009). Global rating of change scales: A review of strengths and weaknesses and considerations for design. The Journal of Manual & Manipulative Therapy, 17(3), 163– 170. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2762832/. 20046623 PMC2762832
- Kendrick, T. and Pilling, S. (2012). Common mental health disorders — identification and pathways to care: NICE clinical guideline. The British Journal of General Practice, 62(594), 47– 49. doi: 10.3399/bjgp12X616481. 22520681 PMC3252532 · DOI
- Kounali, D. Z., Button, K. S., Lewis, G. and Ades, A. E. (2016). The relative responsiveness of test instruments can be estimated using a meta-analytic approach: An illustration with treatments for depression. Journal of Clinical Epidemiology, 77, 68– 77. doi: 10.1016/j.jclinepi.2016.03.005. 26994662 · DOI
- Landis, J. R., & Koch, G. G. (1977). The measurement of observer agreement for categorical data. Biometrics, 33(1), 159– 174. 843571
- Malpass, A., Dowrick, C., Gilbody, S., Robinson, J., Wiles, N., Duffy, L. and Lewis, G. (2016). Usefulness of PHQ-9 in primary care to determine meaningful symptoms of low mood: A qualitative study. The British Journal of General Practice, 66(643), e78– e84. doi: 10.3399/bjgp16X683473. 26823268 PMC4723218 · DOI
- Richards, D. A., Bower, P., Chew-Graham, C., Gask, L., Lovell, K., Cape, J., …, Russell, A. (2016). Clinical effectiveness and cost-effectiveness of collaborative care for depression in UK primary care (CADET): A cluster randomised controlled trial. Health Technology Assessment, 20(14), 1– 192. doi: 10.3310/hta20140. PMC4809468 26910256 · DOI
- Salaminios, G., Duffy, L., Ades, A., Araya, R., Button, K. S., Churchill, R., …, Lewis, G. (2017). A randomised controlled trial assessing the severity and duration of depressive symptoms associated with a clinically significant response to sertraline versus placebo, in people presenting to primary care with depression (PANDA trial): Study protocol for a randomised controlled trial. Trials, 18(1), 496. doi: 10.1186/s13063-017-2253-4. 29065916 PMC5655852 · DOI
- Spiegelhalter, D. J., Best, N. G., Carlin, B. P. and Van Der Linde, A. (2002). Bayesian Measures of model complexity and fit. Journal of the Royal Statistical Society: Series B (Statistical Methodology, 64(4), 583– 639. doi: 10.1111/1467-9868.00353. · DOI · Paper page
- Stucki, G., Daltroy, L., Katz, J. N., Johannesson, M. and Liang, M. H. (1996). Interpretation of change scores in ordinal clinical scales and health status measures: The whole may not equal the sum of the parts. Journal of Clinical Epidemiology, 49(7), 711– 717. 8691219
- Tubach, F., Ravaud, P., Martin-Mola, E., Awada, H., Bellamy, N., Bombardier, C. and … Dougados, M. (2012). Minimum clinically important improvement and patient acceptable symptom state in pain and function in rheumatoid arthritis, ankylosing spondylitis, chronic back pain, hand osteoarthritis, and hip and knee osteoarthritis: Results from a prospective multinational study. Arthritis Care & Research, 64(11), 1699– 1707. doi: 10.1002/acr.21747. 22674853 · DOI · Paper page
- Verkuilen, J. and S, M. (2012). Mixed and mixture regression models for continuous bounded responses using the beta distribution. Journal of Educational And Behavioral Statistics, 37(1), 82– 113.
- Zimprich, D. (2010). Modeling change in skewed variables using mixed beta regression models. Research in Human Development, 7(1), 9– 26.
Cited by
Sorted by citations
Spilg, E. G., Kuk, H., Ananny, L., McNeill, K., LeBlanc, V., Bauer, B. A., Sood, A., & Wells, P. S. (2022) · PLOS ONE · doi:10.1371/journal.pone.0267240 · Cited by 21 · see citing works
Chew, M. T., Chan, C., Kobayashi, S., Cheng, H. Y., Wong, T. M., & Nicholson, L. L. (2023) · Pain Practice · doi:10.1111/papr.13227 · Cited by 18 · see citing works
“However, a paper suggested that a 20% reduction in Patient Health Questionnaire score can be used to indicate clinical improvement for moderately severe depression symptoms.(63) Two studies in our depression meta- analysis used the PHQ9, with all participants starting with depression scores in the severe range.”
MethodNorth American open-label 16-week trial of the MindShift smartphone app for adult anxiety
Rappaport, L. M., Jerome, E., Van Ameringen, M., Whittal, M., & McLean, C. P. (2023) · Journal of Mood & Anxiety Disorders · doi:10.1016/j.xjmad.2023.100036 · Cited by 7 · see citing works
Kishita, N., Gould, R. L., McCracken, L. M., Khondoker, M., Turner, D. A., Ashford, P.-A., Flanagan, E., Czyznikowska, B., Richmond, E., Riggey, M., et al. (2024) · Contemporary Clinical Trials · doi:10.1016/j.cct.2024.107685 · Cited by 3 · see citing works
“This was particularly so for anxiety, which demonstrated an average reduction of 26 % on the General Anxiety Disorder-7 (a reduction of 20 % on this scale is considered to be a minimum clinically important difference [16]).”
Rubaye, S., Shah, A., Aldulaimy, W., Hernandez, A., Park, H., Sorial, V., Prasad, P., & Iyengar, S. (2026) · International Journal of Psychiatry in Clinical Practice · doi:10.1080/13651501.2026.2733584
- Authors
- Kounali, D., Button, K. S., Lewis, G., Gilbody, S., Kessler, D., Araya, R., Duffy, L., Lanham, P., Peters, T. J., Wiles, N., & Lewis, G.
- Affiliations
- University of Bristol (GB)
- University of Bath (GB)
- University College London (GB)
- University of York (GB)
- King's College London (GB)
- Corresponding author
- Kounali, Daphne
- ORCID
- Venue
- Psychological Medicine
- Publisher
- Cambridge University Press (CUP)
- Published
- 2020-11-03
- Volume
- 52
- Issue
- 10
- Pages
- 1875-1882
- ISSN
- 0033-2917 (ISSN-L)
- 1469-8978
- PMC
- PMC9340848
- OpenAlex
- W3080413193
- Cited by
- 164
- References
- 9
- Citations by year
- 2026: 42 · 2025: 38 · 2024: 35 · 2023: 26 · 2022: 13 · 2021: 9 · 2020: 1
- FWCI
- 11.85
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Locations
- Psychological Medicine (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- Research Portal (King's College London) (publishedVersion, other-oa)
- Explore Bristol Research (publishedVersion, cc-by)
- UCL Discovery (University College London) (submittedVersion)
- Funders
- University Hospitals Bristol NHS Foundation Trust
- National Institute for Health and Care Research (RP-PG-0610-10048)
- University of Bristol
- Programme Grants for Applied Research (RP-PG-0610-10048)
- Topics
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes
- Social Sciences › Economics, Econometrics and Finance › Economics and Econometrics › Health Systems, Economic Evaluations, Quality of Life
- Social Sciences › Psychology › Social Psychology › Mental Health Treatment and Access
- Keywords
- minimal clinically important difference, depression, anxiety, PHQ-9, Beck Depression Inventory-II, GAD-7, global rating of change, baseline symptom severity, primary care
- MeSH terms
- Depression, United Kingdom, Humans, Longitudinal Studies, Primary Health Care, Prospective Studies
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
