Background. —Clinical prediction rules are decision-making tools for clinicians, containing variables from the history, physical examination, or simple diagnostic tests. Objective. —To review the quality of recently published clinical prediction rules and to suggest methodological standards for their development and evaluation. Data Sources. —Four general medical journals were manually searched for clinical prediction rules published from 1991 through 1994. Study Selection. —Four hundred sixty potentially eligible reports were identified, of which 30 were clinical prediction rules eligible for study. Most methodological standards could only be evaluated in 29 studies. Data Abstraction. —Two investigators independently evaluated the quality of each report using a standard data sheet. Disagreements were resolved by consensus. Data Synthesis. —The mathematical technique was used to develop the rule, and the results of the rule were described in 100% (29/29) of the reports. All the rules but 1 (97% [28/29]) were felt to be clinically sensible. The outcomes and predictive variables were clearly defined in 83% (24/29) and 59% (17/29) of the reports, respectively. Blind assessment of outcomes and predictive variables occurred in 41% (12/29) and 79% (23/29) of the reports, respectively, and the rules were prospectively validated in 79% (11/14). Reproducibility of predictive variables was assessed in only 3% (1/29) of the reports, and the effect of the rule on clinical use was prospectively measured in only 3% (1/30). Forty-one percent (12/29) of the rules were felt to be easy to use. Conclusions. —Although clinical prediction rules comply with some methodological criteria, for other criteria, better compliance is needed.

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=JAMA&articleId=414118&pdfFileName=jama_277_6_034.pdf

Clinical prediction rules. A review and suggested modifications of methodological standards.

Background Comparing stroke rates in different parts of the world and at different points in time may increase our understanding of the disease. Comparisons are only meaningful if they are based on studies that use similar definitions, methods, and data presentation. 

Summary of Review We discuss the criteria that make such studies comparable, drawing on the experiences of recent studies performed around the world. If only those studies that fulfill the proposed criteria for comparison are considered, comparable data do not exist for vast areas of the world, including Africa, Asia, and South America. The importance of complete, community-based case ascertainment, including strokes managed outside the hospital, is emphasized. An approach for measuring and comparing the incidence of the pathological types of stroke (cerebral infarction, primary intracerebral hemorrhage, and subarachnoid hemorrhage) and subtypes of cerebral infarction is suggested. 

Conclusions The “ideal” stroke incidence study does not exist, but studies closely approaching it will reveal the most reliable and comparable results. There is a need for further studies to fill the gaps in our knowledge of the worldwide incidence of stroke, particularly for developing countries.

Comparing Stroke Incidence Worldwide What Makes Studies Comparable

This article represents the recommendations for the management of spontaneous intracerebral haemorrhage of the European Stroke Initiative (EUSI) These recommendations are endorsed by the 3 European societies which are represented in the EUSI: the European Stroke Council, the European Neurological Society and the European Federation of Neurological Societies

Recommendations for the Management of Intracranial Haemorrhage – Part I: Spontaneous Intracerebral Haemorrhage

Summary Background In patients with acute stroke, rapid intervention is crucial to maximise early treatment benefits. Stroke patients commonly have their first contact with medical staff in the emergency room (ER). We designed and validated a stroke recognition tool—the Recognition of Stroke in the Emergency Room (ROSIER) scale—for use by ER physicians. Methods We prospectively collected data for 1 year (development phase) on the clinical characteristics of patients with suspected acute stroke who were admitted to hospital from the ER. We used logistic regression analysis and clinical reasoning to develop a stroke recognition instrument for application in this setting. Patients with suspected transient ischaemic attack (TIA) with no symptoms or signs when assessed in the ER were excluded from the analysis. The instrument was assessed using the baseline 1-year dataset and then prospectively validated in a new cohort of ER patients admitted over a 9-month period. Findings In the development phase, 343 suspected stroke patients were assessed (159 stroke, 167 non-stroke, 32 with TIA [17 with symptoms when seen in ER]). Common stroke mimics were seizures (23%), syncope (23%), and sepsis (10%). A seven-item (total score from −2 to +5) stroke recognition instrument was constructed on the basis of clinical history (loss of consciousness, convulsive fits) and neurological signs (face, arm, or leg weakness, speech disturbance, visual field defect). When internally validated at a cut-off score greater than zero, the instrument showed a diagnostic sensitivity of 92%, specificity of 86%, positive predictive value (PPV) of 88%, and negative predictive value (NPV) of 91%. Prospective validation in 173 consecutive suspected stroke referrals (88 stroke, 59 non-stroke, 26 with TIA [13 with symptoms]) showed sensitivity of 93% (95% CI 89–97), specificity 83% (77–89), PPV 90% (85–95), and NPV 88% (83–93). The ROSIER scale had greater sensitivity than existing stroke recognition instruments in this population. Interpretation The ROSIER scale was effective in the initial differentiation of acute stroke from stroke mimics in the ER. Introduction of the instrument improved the appropriateness of referrals to the stroke team.

https://www.thelancet.com/pdfs/journals/laneur/PIIS1474-4422(05)70201-5.pdf

The Recognition of Stroke in the Emergency Room (ROSIER) scale: development and validation of a stroke recognition instrument.

ContextPatients suspected of having a stroke or transient ischemic attack require
accurate assessment for appropriate acute treatment and use of secondary preventive
interventions.ObjectiveTo update a 1994 systematic review of the accuracy and reliability of
symptoms and findings on neurological examination for the evaluation of patients
with suspected stroke or transient ischemic attack.Data SourcesWe identified potential articles dated between 1994 and 2005 by multiple
search strategies of the MEDLINE database and review of article and textbook
bibliographies along with private collections.Study SelectionSelected articles provided primary data or appropriate summary statistics
of the accuracy and/or reliability of the history or physical examination
for diagnosis or short-term prognosis of patients with neurological signs
prompting a consideration of stroke. Articles addressing accuracy also needed
to provide a final diagnosis following neuroimaging and all relevant laboratory
tests.Data ExtractionThe authors reviewed and abstracted data for estimating sensitivities,
specificities, positive and negative likelihood ratios (LRs). Reliability
assessment was based on reported kappa (κ) statistics or intraclass
correlation coefficients as appropriate.Data SynthesisThe prior probability of a stroke among patients with neurologically
relevant symptoms is 10%. Based on studies using modern neuroimaging, the
presence of acute facial paresis, arm drift, or abnormal speech increases
the likelihood of stroke (LR of ≥1 finding = 5.5; 95% CI, 3.3-9.1),
while the absence of all 3 decreases the odds (LR of 0 findings = 0.39;
95% CI, 0.25-0.61). The accurate determination of stroke subtype requires
neuroimaging to distinguish ischemic from hemorrhagic stroke. Early mortality
increases among those with any combination of impaired consciousness, hemiplegia,
and conjugate gaze palsy (LR of ≥1 finding = 1.8; 95% CI, 1.2-2.8
and LR of 0 findings = 0.36; 95% CI, 0.13-1.0). Symptoms associated
with high agreement for the diagnosis of stroke or transient ischemic attack
vs no vascular event are a sudden change in speech, visual loss, diplopia,
numbness or tingling, paralysis or weakness, and non-orthostatic dizziness
(κ = 0.60; 95% CI, 0.52-0.68). The reliabilities of individual
neurological findings vary from slight to almost perfect, but can be improved
with standardized scoring systems such as the National Institutes of Health
Stroke Scale. Based on examination findings, stroke vascular distribution
can be determined with moderate to good reliability (κ = 0.54;
95% CI, 0.39-0.68).ConclusionsThe history and clinical findings provide the basis for evaluating patients
with possible stroke and choosing appropriate treatments. Focusing on 3 findings
(acute facial paresis, arm drift, or abnormal speech) might improve diagnostic
accuracy and reliability.

/pdf/is-this-patient-having-a-stroke-44z4ornbnz.pdf

Is This Patient Having a Stroke

OBJECTIVES--To develop a simple, reliable, and safe diagnostic tool for acute stroke syndromes in a setting where computerised brain scanning was not readily available and to validate its accuracy with regard to pathological types of stroke. DESIGN--13 clinical variables that potentially might differentiate supratentorial cerebral haemorrhage from infarction were recorded and tested by multivariate analysis in a prospective study of 174 patients with acute stroke. In developing the Siriraj stroke score stepwise discriminant analysis of the variables was followed by a linear discriminant equation to differentiate between supratentorial haemorrhage and infarction. The score obtained was validated against scores in 206 other patients with stroke, computerised brain scans being used for definitive diagnosis. SETTING--Siriraj Hospital Medical School, Mahidol University, Bangkok. SUBJECTS--Prospective study: 174 consecutive patients with acute supratentorial stroke syndrome (not subarachnoid haemorrhage) admitted to Siriraj Hospital during 1984-5; validation study: 206 patients admitted to Siriraj Hospital or another hospital for supratentorial intracerebral haemorrhage or infarction. RESULTS--The Siriraj stroke score was developed and calculated as (2.5 x level of consciousness) + (2 x vomiting) + (2 x headache) + (0.1 x diastolic blood pressure) - (3 x atheroma markers) - 12. A score above 1 indicates supratentorial intracerebral haemorrhage, while a score below -1 indicates infarction. The score between 1 and -1 represents an equivocal result needing a computerised brain scan or probability curve to verify the diagnosis. In the validation study of the Siriraj stroke score the diagnostic sensitivities of the score for cerebral haemorrhage and cerebral infarction were 89.3% and 93.2% respectively, with an overall predictive accuracy of 90.3%. CONCLUSION--The Siriraj stroke score is widely accepted and applied in hospitals throughout Thailand as a simple and reliable bedside method for diagnosing acute stroke.

https://www.bmj.com/content/bmj/302/6792/1565.full.pdf

A Viriyavejakul

Papers

Siriraj stroke score and validation study to distinguish supratentorial intracerebral haemorrhage from infarction.