Pre-operative Haemorrhagic Risk Clinical Trial
Official title:
Pre-operative Haemorrhagic Risk Screening, Using a Standardized Questionnaire Before Scheduled Surgeries.
"This is not a validation study of a questionnaire. This is a multicenter diagnostic study,
assessing the sensitivity and specificity of a simple structured questionnaire, to identify
patients requiring further haemostatic investigations, in pre-operative patients. This study
will also allow for the assessment of the sensitivity and specificity of the routine care
strategy.
All patients are recruited during the pre-anaesthesia visit by an anaesthesiologist, in
different anaesthetic sectors each day of the week, so that different types of surgery are
represented.
Each day (from Monday to Friday), the first 2 eligible patients will be offered to take part
in the study.
Routine care strategy is not modified by the study protocol. In addition, the simple
structured questionnaire will be completed by the patient with a research assistant after the
pre-operative consultation As recommended in diagnostic studies, the gold standard (see
secondary endpoint paragraph) will be performed consistently in all patients to avoid
verification bias.
The improvement of screening for the need of further investigations by use of the
questionnaire compared to routine care will be measured counting how many patients are
adequately reclassified with the questionnaire compared to the routine care strategy,
regarding the gold standard (using the Net Reclassification Index)."
"Screening for the need of an extensive haematological investigation in order to determine
the existence of inherited or acquired haemostatic abnormalities at the pre-anaesthesia visit
is part of a routinely used strategy to prevent perioperative haemorrhagic complications. In
France, this screening is mainly based on a basic set of haemostatic tests: prothrombin time
(PT), activated partial thromboplastin time (aPTT) and platelet count (PC). When these tests
are abnormal, the patient may undergo a more complete set of haemostatic tests and, if
needed, be referred to a haematologist for advice. Nevertheless, all published studies have
pointed out the scarce efficacy of preoperative PT/aPTT/PC testing for hemorrhagic risk
assessment.
Therefore, in 2011 several professional societies have advised AGAINST using this strategy
and advocated its replacement by a structured questionnaire for the screening of the need of
further haemostatic investigations (to validate or not an increased risk of perioperative
haemorrhage). Nevertheless, the performance of a screening strategy relying on such a
structured questionnaire has never been studied in the pre-anaesthesia context. This probably
explains why many anaesthesiologists still continue to prescribe PT/aPTT/PC to detect
haemostatic abnormalities and don't use any questionnaire.
Thus, our hypothesis is that a validated structured and simple questionnaire is an accurate
screening strategy to determine patients requiring further haemostatic investigations in the
preoperative setting.
One of the main reasons for the non compliance with the guidance advising against the use of
screening haemostatic tests (PT/aPTT/PC) for the identification of patients with potential
haemorrhagic risk is probably related to the fact that the alternative strategy proposed to
anaesthesiologists (the use of a structured questionnaire) has never been investigated before
in the context of the pre-anaesthesia visit. Therefore, the present project would estimate
the diagnostic performance (sensitivity and specificity) of a simple structured questionnaire
to identify patients requiring further haemostatic investigations (i.e. patients for whom
further haemostatic investigations would conclude to an increase haemorrhagic risk). The
innovative approach of the project is related to: (i) the choice of a simple structured
questionnaire, specifically conceived to be used at the pre-anaesthesia visit; (ii) a study
design that takes into account the needs of the final users (the anaesthesiologist and the
surgical team).
To estimate the diagnostic accuracy of a questionnaire at the pre-anaesthesia visit, to
identify patients requiring further haemostatic investigations for haemorrhagic risk
assessment as defined by a full haemostatic investigation (i.e. patients for whom full
haemostatic investigations would conclude to an increase haemorrhagic risk)
- To estimate the diagnostic accuracy (specificity, sensibility and likelihood ratios) of
the current routine care strategy at the pre-anaesthesia visit (i.e. no structured
questionnaire, and prescription of further haematological tests at the sole discretion
of the anaesthesiologist) to identify patients requiring further haemostatic
investigations for HgR as defined by the gold standard (a full haemostatic
investigation).
- To measure the improvement in the identification of patients requiring further
haemostatic investigations for HgR assessment using a simple structured questionnaire,
compared to usual care, in pre-operative patients (i.e. to describe how many patients
are adequately reclassified by using the questionnaire).
- To describe how many patients had a major peri-operative bleeding event with respect to
the answers to the simple structured questionnaire."
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