A Survey of Cerebrospinal Fluid Total Protein Upper Limits in Canada: Time for an Update?
Bibliographic record
Abstract
BACKGROUND: The antiquated standard reference range of 0.15-0.45 g/L for cerebrospinal fluid total protein (CSF-TP) is well entrenched in medical literature and laboratory operating procedures across the world. METHODS: We conducted a web-based survey with a response rate of 34.9% through the listserv of the Canadian Neurological Sciences Federation. Additional laboratory reference data were collated by telephone interview of hospital laboratory technologists across Canada. RESULTS: A total of 142 site responses were obtained: 64.1% from academic/tertiary hospitals and 35.9% from community hospitals. A strong majority (80.4%) of both types of institutions reported using a CSF-TP upper reference limit of 0.45 g/L or less. As a rule, no age adjustments were implemented in CSF-TP-level interpretation. CONCLUSIONS: Recent well-powered laboratory reference studies have documented CSF-TP upper reference limits that are above 0.6 g/L starting at age 50, with incremental limits partitioned by subsequent decades of age. The conventional 0.45 g/L limit could lead to false positive results. Our survey suggests there is a need to consider a wide adoption of data-driven, rather than historical, reference values.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.008 | 0.024 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.004 | 0.013 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".