Dichotomizing rating scale scores in psychiatry: a bad idea?
Open accessAbstract
In psychiatry, the use of rating scales as measures of outcome in clinical trials allows us to generate continuous outcome data, where each individual's outcome is measured in numbers. Continuous outcomes can be divided into two categories, such as improved and not improved, or may be kept continuous. This article briefly presents the main advantages and disadvantages of these two approaches, which are commonly employed in the analyses of rating scale scores in clinical trials and systematic reviews.
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?
Categorising a continuous outcome leads to loss of information.
“Categorising a continuous outcome leads to loss of information.38 39 40”
From Developing clinical prediction models: a step-by-step guide (2024) · cites this paper as [40]
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
Effectiveness of Antipsychotic Drugs in Patients with Chronic Schizophrenia
Lieberman, J. A., Stroup, T. S., McEvoy, J. P., Swartz, M. S., Rosenheck, R. A., Perkins, D. O., Keefe, R. S. E., Davis, S. M., Davis, C. E., Lebowitz, B. D., et al. (2005) · New England Journal of Medicine · doi:10.1056/nejmoa051688 · Cited by 5,892 · see citing works
The cost of dichotomising continuous variables
Altman, D. G., & Royston, P. (2006) · BMJ · doi:10.1136/bmj.332.7549.1080 · Cited by 2,688 · see citing works
Interpreting treatment effects in randomised trials
Guyatt, G. H., Juniper, E. F., Walter, S. D., Griffith, L. E., & Goldstein, R. S. (1998) · BMJ · doi:10.1136/bmj.316.7132.690 · Cited by 516 · see citing works
Efficacy of antidepressants in adults
Moncrieff, J., & Kirsch, I. (2005) · BMJ · doi:10.1136/bmj.331.7509.155 · Cited by 329 · see citing works
Barbui, C., Furukawa, T. A., & Cipriani, A. (2007) · Canadian Medical Association Journal · doi:10.1503/cmaj.070693 · Cited by 121 · see citing works
Self-citationExplanatory and pragmatic trials
Barbui, C., Veronese, A., & Cipriani, A. (2007) · Epidemiologia e Psichiatria Sociale · doi:10.1017/s1121189x00004735 · Cited by 10 · see citing works
Self-citation
Flagged first, then by citations
Cited by
Sorted by citations
Developing clinical prediction models: a step-by-step guide
Efthimiou, O., Seo, M., Chalkou, K., Debray, T., Egger, M., & Salanti, G. (2024) · BMJ · doi:10.1136/bmj-2023-078276 · Cited by 544 · see citing works
Sehatzadeh, S., Daskalakis, Z. J., Yap, B., Tu, H.-A., Palimaka, S., Bowen, J. M., & O’Reilly, D. J. (2019) · Journal of Psychiatry and Neuroscience · doi:10.1503/jpn.180056 · Cited by 104 · see citing works
Stevanović, D., Urbán, R., Atilola, O., Vostanis, P., Balhara, Y. P. S., Avicenna, M., Kandemır, H., Knez, R., Franić, T., & Petrov, P. (2014) · Epidemiology and Psychiatric Sciences · doi:10.1017/s2045796014000201 · Cited by 71 · see citing works
Đorić, A., Stevanović, D., Stupar, D., Vostanis, P., Atilola, O., Moreira, P., Dodig‐Ćurković, K., Franić, T., Davidović, N., Avicenna, M., et al. (2019) · European Journal of Psychotraumatology · doi:10.1080/20008198.2019.1605282 · Cited by 59 · see citing works
Biehl, R., Boecking, B., Brüeggemann, P., Grosse, R., & Mazurek, B. (2020) · Frontiers in Psychology · doi:10.3389/fpsyg.2019.03093 · Cited by 49 · see citing works
Hutton, P., Rienzo, F. D., Turkington, D., Spencer, H. M., & Taylor, P. J. (2018) · Schizophrenia Bulletin · doi:10.1093/schbul/sby153 · Cited by 22 · see citing works
Delluc, A., Ghanima, W., Kovacs, M. J., Shivakumar, S., Kahn, S. R., Sandset, P. M., Kearon, C., Mallick, R., & Rodger, M. A. (2022) · Thrombosis Research · doi:10.1016/j.thromres.2022.03.014 · Cited by 22 · see citing works
Zhou, S., & Fang, Y. (2022) · Brain Sciences · doi:10.3390/brainsci12070943 · Cited by 17 · see citing works
The number of response categories in ordered response models
Iannario, M., Monti, A. C., & Scalera, P. (2021) · The International Journal of Biostatistics · doi:10.1515/ijb-2021-0013 · Cited by 14 · see citing works
Qi, L., Wang, S., Li, X., Yu, Y., Wang, W., Li, Q., Tian, Y., Bai, T., & Wang, K. (2024) · Journal of Psychiatric Research · doi:10.1016/j.jpsychires.2024.07.046 · Cited by 14 · see citing works
Utsumi, T., Ishitsuka, N., Noro, T., Suzuki, Y., Iijima, S., Sugizaki, Y., Somoto, T., Oka, R., Endo, T., Kamiya, N., et al. (2025) · International Journal of Urology · doi:10.1111/iju.70075 · Cited by 12 · see citing works
Ostuzzi, G., Bighelli, I., Carrara, B.-V., Dusi, N., Imperadore, G., Lintas, C., Nifosì, F., Nosè, M., Piazza, C., Purgato, M., et al. (2013) · International Journal of Mental Health Systems · doi:10.1186/1752-4458-7-14 · Cited by 11 · see citing works
Self-citationChildhood emotional maltreatment and sensitivity to social rejection in emerging adults
Euteneuer, F., Lass‐Hennemann, J., Pfundmair, M., Salzmann, S., & Kuehl, L. K. (2023) · Child Abuse & Neglect · doi:10.1016/j.chiabu.2023.106604 · Cited by 11 · see citing works
Prediction of antipsychotics efficacy based on a polygenic risk score: a real-world cohort study
Pieri, M. D., Ferrari, M., Pistis, G., Gamma, F., Marino, F., von Gunten, A., Conus, P., Cosentino, M., & Eap, C. B. (2024) · Frontiers in Pharmacology · doi:10.3389/fphar.2024.1274442 · Cited by 9 · see citing works
Ugwu, G. C., Jalali, F., Liu, G., Li, G., Langendijk, J. A., & Alizadeh, B. Z. (2025) · Radiotherapy and Oncology · doi:10.1016/j.radonc.2025.111350 · Cited by 7 · see citing works
Adeyinka, D. A., Novik, N., Novotná, G., Bartram, M. H., Gabrys, R. L., & Muhajarine, N. (2023) · BMC Psychiatry · doi:10.1186/s12888-023-05051-w · Cited by 7 · see citing works
Hiilamo, A. (2024) · Social Indicators Research · doi:10.1007/s11205-024-03314-x · Cited by 5 · see citing works
Euteneuer, F., Neubert, M., Salzmann, S., Fischer, S., Ehlert, U., & Rief, W. (2024) · Journal of Psychosomatic Research · doi:10.1016/j.jpsychores.2024.111885 · Cited by 4 · see citing works
Purgato, M., Albanese, E., Papola, D., Prina, E., Tedeschi, F., Gross, A. L., Sijbrandij, M., Acartürk, C., Annoni, A. M., Silva, M., et al. (2024) · BMJ Open · doi:10.1136/bmjopen-2023-082652 · Cited by 3 · see citing works
Self-citationNyoni, P., Tomita, A. M., Mkhwanazi, S., & Gibbs, A. (2024) · International Journal of Social Psychiatry · doi:10.1177/00207640241306062 · Cited by 2 · see citing works
Stress Appraisal Measure: Investigating the Factor Structure and Validity in the French Language
Grimm, E., Francia, L., & Agrigoroaei, S. (2024) · Assessment · doi:10.1177/10731911231223120 · Cited by 2 · see citing works
Triadic shared decision making in emergency psychiatry: an explorative study
van Asperen, G. C. R., Ai, W., de Winter, R. F. P., & Mulder, C. L. (2025) · BMC Psychiatry · doi:10.1186/s12888-025-06640-7 · Cited by 2 · see citing works
Säwén, A., Odzakovic, E., Fridlund, B., Björk, M., & Broström, A. (2026) · Asian Journal of Social Health and Behavior · doi:10.4103/shb.shb_388_25 · Cited by 1 · see citing works
Marume, A., Archary, M., January, J., & Mahomed, S. (2026) · African Journal of Primary Health Care & Family Medicine · doi:10.4102/phcfm.v18i1.5369
Ugwu, G., Jalali, F., Liu, G., Li, G., Langendijk, J. A., & Alizadeh, B. Z. (2025) · SSRN Electronic Journal · doi:10.2139/ssrn.5355709
Lian, J., Zuccolo, P. F., Ebrahimi, O. V., Fatori, D., Adlakha, A., Hoz, J. D. L., Lee, Y. A., Carneiro, A. M., Benseñor, I. M., Lotufo, P. A., et al. (2025) · medRxiv · doi:10.1101/2025.09.09.25335409
Maternal Depressive Symptoms and Child Injury Risk
Bryant, L. A., & Morrongiello, B. A. (2025) · Maternal and Child Health Journal · doi:10.1007/s10995-025-04193-5
Adeyinka, D. A., Novik, N., Novotná, G., Bartram, M. H., Gabrys, R. L., & Muhajarine, N. (2023) · Figshare · doi:10.6084/m9.figshare.23908786
Adeyinka, D. A., Novik, N., Novotná, G., Bartram, M. H., Gabrys, R. L., & Muhajarine, N. (2023) · Figshare · doi:10.6084/m9.figshare.23908789
Shen, Y., Li, F., Zhang, Q. P., Zhang, Y., Ren, Y., Liu, W. T., & Liu, Y. (2026) · BMC Medical Education · doi:10.1186/s12909-026-09472-5
Análise do questionário de saúde do paciente durante a pandemia da covid-19 via TRI
Santos-Souza, M. H., da Silva-Ferraz, B. F. P., Palhano, D. B., & Faro, A. (2026) · Psico · doi:10.15448/1980-8623.2026.1.47284
Lian, J., Zuccolo, P. F., Ebrahimi, O. V., Fatori, D., Adlakha, A., Hoz, J. D. L., Lee, Y. A., Carneiro, A. M., Benseñor, I. M., Lotufo, P. A., et al. (2026) · International Journal of Methods in Psychiatric Research · doi:10.1002/mpr.70102 · Cited by 1 · see citing works
Qi, L., Yu, Y., Pan, X., Jin, L., Gao, Z., Zhang, T., Wang, W., Wang, K., Li, Q., & Bai, T. (2026) · ALPHA PSYCHIATRY · doi:10.31083/ap47383
- Authors
- Purgato, M., & Barbui, C.
- Affiliations
- University of Verona (IT)
- Corresponding author
- Purgato, M.
- Venue
- Epidemiology and Psychiatric Sciences
- Publisher
- Cambridge University Press (CUP)
- Published
- 2012-10-23
- Volume
- 22
- Issue
- 1
- Pages
- 17-19
- ISSN
- 2045-7960 (ISSN-L)
- 2045-7979
- PMC
- PMC6998334
- OpenAlex
- W2328803923
- Cited by
- 33
- References
- 6
- Citations by year
- 2026: 6 · 2025: 6 · 2024: 8 · 2023: 4 · 2022: 2 · 2021: 1 · 2020: 1 · 2019: 2 · 2018: 1 · 2014: 1 · 2013: 1
- FWCI
- 0.61
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Epidemiology and Psychiatric Sciences (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Epidemiology
- Keywords
- dichotomization, continuous outcomes, clinical trials, treatment response, systematic reviews
- MeSH terms
- Humans, Psychiatry
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