study11 fields
| study_design | RCTNon-randomized TrialProspective CohortRetrospective CohortCase-ControlCross-sectionalOther | Study design classification. RCT requires TRUE random allocation (computer-generated sequence, random-number table, sealed random envelopes). A controlled comparison where the investigator assigned the intervention by a systematic non-random rule — alternation, enrolment date/month, record number, odd/even — is a Non-randomized Trial, NOT a cohort. Do not classify RCT on the word 'randomized' alone; check the described allocation method. Cohort/Case-Control/Cross-sectional apply only to observational studies where exposure is not investigator-assigned; for those, forward data collection = Prospective Cohort, existing records = Retrospective Cohort. |
| country | text | Country of patient enrollment. MUST use ISO 3166-1 short names, except: always write 'UK' (not 'United Kingdom') and 'USA' (not 'United States of America' or 'United States'). Multiple countries comma-separated, alphabetical. Use country of enrollment, not author affiliation (e.g., 'France, Spain, UK, USA'). |
| center_type | singlemulti | Single-center or multicenter study. Multicenter requires patients enrolled at >=2 distinct sites. National registry studies = Multicenter. |
| enrollment_criteria | textharmonize | Key inclusion AND exclusion criteria as reported. Limit to 5-7 criteria: age, condition, procedure, severity, exclusions (prefix with 'no'). Use parentheses to group alternatives with 'or' (e.g., 'age >=18 & (hip or knee) arthroplasty & ASA I-III & no revision surgery'). |
| enrollment_period | textharmonize | Date range of patient enrollment. Format: 'YYYY-MM to YYYY-MM' or 'YYYY to YYYY' if months not reported. Use enrollment dates, not publication or data collection dates (e.g., '2015-01 to 2020-12'). |
| funding_source | IndustryNon-industryMixedDeclared none | Primary funding source AND/OR conflict-of-interest disclosure. Industry = any pharmaceutical/device/commercial company funded the work. Non-industry = government/academic/foundation/charity only. Mixed = both. Declared none = positive disclosure of no funding or no COI with no offsetting positive funding signal. When a positive funding signal is present, use that; only fall through to Declared none if no funding source is named. |
| sample_size_total | number | Total participants allocated/enrolled across the on-axis arms — the sum of the per-unit sample_size (the pre-attrition denominator), matching that field's stage. Not the screened, eligible, or source-population/registry denominator, and not the analyzed/complete-case total. If not explicitly stated, sum the per-unit sample_size values. |
| data_source | textharmonize | Primary data source for the analysis. Format as a short noun phrase that names the source type and, when specified, the named registry or database (e.g., 'institutional database', 'national registry', 'UNOS/OPTN registry', 'NHANES', 'claims database', 'prospective single-center cohort'). When the paper draws from multiple sources, comma-separate. Use the source named in Methods, not author affiliation. |
| surgery_type | textharmonize | Type(s) of surgery in the study population as a short noun phrase drawn from the paper's population description (e.g., "cardiac surgery", "elective orthopedic", "major abdominal"). When multiple distinct surgery classes are enrolled, comma-separate the principal classes. Use the operative procedure category, not the underlying disease alone. |
| anesthetic_type | generalneuraxialperipheral_regionalcombination | Predominant anesthetic modality for the index procedure. general = general anesthesia alone; neuraxial = spinal or epidural (with or without sedation) and no general; peripheral_regional = peripheral nerve block without neuraxial or general as the primary modality; combination = more than one of the above modalities used across the cohort or within patients (e.g., general plus epidural). Keep neuraxial and peripheral_regional distinct — do not merge under a single 'regional' label. Classify from the methods' anesthetic description; not_reported when the paper is silent on anesthetic modality. |
| preop_cognitive_assessment | text | Whether a baseline cognitive assessment was performed before the cognitive intervention, its timing (strictly preoperative vs post-surgery-but-pre-intervention), and whether patients with preexisting cognitive impairment were identified, graded, or excluded. Format as a short phrase covering both assessment/timing and impairment handling (e.g., "MoCA preoperatively, impairment excluded"; "baseline battery post-CABG pre-intervention, impairment not graded"; "no preoperative assessment"). not_reported only when the paper is silent on BOTH a baseline assessment and impairment handling. |