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Postoperative Outcomes Following Preweekend Surgery

2025· article· en· W4408149344 on OpenAlexaffabout
Sanjana Ranganathan, Carlos Riveros, Yusuke Tsugawa, Michael Geng, Vatsala Mundra, Zachary Melchiode, Bheeshma Ravi, Natalie G. Coburn, Angela Jerath, Allan S. Detsky, Christopher J.D. Wallis, Raj Satkunasivam

Bibliographic record

VenueJAMA Network Open · 2025
Typearticle
Languageen
FieldMedicine
TopicHospital Admissions and Outcomes
Canadian institutionsUniversity Health NetworkHealth Sciences CentreUniversity of TorontoMount Sinai HospitalSunnybrook Health Science Centre
FundersNational Institute on Minority Health and Health DisparitiesNational Institute on Aging
KeywordsMedicineWeekend effectCohortRetrospective cohort studySurgeryCohort studyPopulationEmergency medicineInternal medicine

Abstract

fetched live from OpenAlex

Importance: The phenomenon of a weekend effect refers to a higher potential for adverse outcomes in patients receiving care over the weekend. Few prior studies have comprehensively investigated the effects of postoperative weekend care on surgical outcomes in a generalizable cohort. Objective: To examine differences in short-term and long-term postoperative outcomes of patients undergoing surgical procedures immediately before vs after the weekend. Design, Setting, and Participants: This is a population-based, retrospective cohort secondary analysis of adult patients in Ontario, Canada, undergoing 1 of 25 common surgical procedures between January 1, 2007, to December 31, 2019, with 1 year of follow-up. Data analysis was performed from October to November 2022. Exposure: Undergoing surgery before (1 day before) vs after (1 day after) the weekend. Main Outcomes and Measures: The primary outcome was a composite of death, readmission, and complications at 30 days, 90 days, and 1 year. Multivariable generalized estimating equations with an independent correlation structure, accounting for covariates, with clustering on surgical procedure were used to estimate the association between day of surgery in relation to the weekend and the outcomes. Results: Of the 429 691 patients (mean [SD] age, 58.6 [16.9] years; 270 002 female patients [62.8%]) in the study cohort, 199 744 (46.5%) underwent surgery before the weekend, and 229 947 (53.5%) underwent surgery after the weekend. Patients in the preweekend group were more likely than those in the postweekend group to experience the composite outcome of death, complications, and readmissions at 30 days (adjusted odds ratio [aOR], 1.05; 95% CI, 1.02-1.08), 90 days (aOR, 1.06; 95% CI, 1.03-1.09), and 1 year (aOR, 1.05; 95% CI, 1.02-1.09) after surgery. Odds of mortality were increased in the preweekend group vs the postweekend group at 30 days (aOR, 1.09; 95% CI, 1.03-1.16), 90 days (aOR, 1.10; 95% CI, 1.03-1.17), and 1 year (aOR, 1.12; 95% CI, 1.08-1.17). Conclusions and Relevance: In this retrospective multi-institutional study, patients who underwent surgery immediately preceding the weekend had a significantly increased risk of complications, readmissions, and mortality compared with those treated after the weekend. Further study is needed to understand differences in care that may underpin these observations and ensure that patients receive high-quality care regardless of the day of the week.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.001
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.114
Threshold uncertainty score0.508

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.023
GPT teacher head0.333
Teacher spread0.309 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

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Citations6
Published2025
Admission routes2
Has abstractyes

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