Calculation of PPV, sensitivity, specificity, NPV and stroke prevalence.

<p>PPV = positive predictive value; NPV = negative predictive value. Stroke prevalence = (TP+ FN) / (TP+FP+FN+TN).</p

Study selection flow diagram.

<p>* Reference standard is cerebrovascular disease, or includes TIA, or uses ICD codes for stroke. ^† <50 self-reports of stroke validated, or number unpublished.</p

The proportion of self-reported strokes which were true stroke, true TIA or either.^*

<p>TIA = Transient ischemic attack.</p><p>*According to the reference standard.</p><p>^†Studies which published sufficient data (out of 17 included studies).</p><p>^‡Participants were asked to report stroke, or stroke plus transient ischemic attack (TIA) (+/- synonyms for either).</p><p>The proportion of self-reported strokes which were true stroke, true TIA or either.^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137538#t001fn002" target="_blank">*</a>}</p

Positive predictive values of codes for stroke.

<div><p>H: hospital data, D: death certificates, H+D: hospital data and death certificates; x = number of coded events confirmed as ‘true cases’ by the reference standard; y = total number of coded events; x/y = PPV. Circles represent PPVs, and horizontal lines denote 95% confidence intervals (CIs). Circle size is proportional to the inverse variance of the PPV. Where more than one result was available for a particular study, the result for the largest number of coded events validated is shown.</p> <p>* Cerebrovascular codes: I60-I69+/-G45 (ICD-10) or 430–438 (ICD-9), unless otherwise specified</p> <p>† Mean PPV (taken from the range published in the study)</p> <p>‡ Excluding codes 435 (TIA) and 438 (sequelae of cebrovascular disease)</p> <p>§ Excluding code 435 (TIA) and including code 342 (hemiplegia and hemiparesis)</p> <p>¶ Excluding code 435 (TIA)</p> <p># Stroke-specific codes: 160, 161, 163, 164 (ICD-10), 430, 431, 434, 436 (ICD-9), 430, 431, 433.x1, 434.x1 (ICD-9-CM).</p> <p>¥ Ischaemic stoke and unspecified stroke codes: I63, I64 (ICD-10), 434, 436 (ICD-9), 433.x1, 434.x1, 436 (ICD-9-CM)</p> <p>**Ischaemic stroke codes:163 (ICD-10), 434 (ICD-9), 433.x1, 434.x1 (ICD-9-CM)</p> <p>†† Haemorrhagic stroke codes:I60, I61 (ICD-10), 430, 431 (ICD-9)</p> <p>‡‡ Subarachnoid haemorrhage stroke codes:I60 (ICD-10), 430 (ICD-9)</p> <p>¶¶ Intracerebral haemorrhage stroke codes:I61 (ICD-10), 431 (ICD-9)</p></div

Positive predictive values of codes for ischaemic stroke.

<div><p>H: hospital data, D: death certificates, H+D: hospital data and death certificates; x = number of coded events confirmed as ‘true cases’ by the reference standard; y = total number of coded events; x/y = PPV. Circles represent PPVs, and horizontal lines denote 95% confidence intervals (CIs). Circle size is proportional to the inverse variance of the PPV. Where more than one result was available for a particular study, the result for the largest number of coded events validated is shown.</p> <p>† Mean PPV (taken from the range published in the study)</p> <p>¥ Ischaemic stoke and unspecified stroke codes: I63, I64 (ICD-10), 434, 436 (ICD-9), 433.x1, 434.x1, 436 (ICD-9-CM)</p> <p>**Ischaemic stroke codes:163 (ICD-10), 434 (ICD-9), 433.x1, 434.x1 (ICD-9-CM)</p></div

International Classification of Diseases (ICD) codes for cerebrovascular disease.

<div><p>* 433: occlusion/stenosis of pre-cerebral arteries <i>with or without infarction</i>. † 434: thrombosis/embolism of cerebral arteries <i>with or without infarction</i>. Codes in blue text denote ICD-9 codes which most closely represent stroke when subdivided using additional coding available in the clinically modified version of ICD-9 (ICD-9-CM) used in North America. In ICD-9-CM, <i>‘with infarction’</i> (433.x1, 434.x1) is distinguished from ‘<i>without infarction’</i> (433.x0, 434.x0).</p> <p>‡ 436: acute, ill-defined cerebrovascular disease</p> <p>¶ a pathological term for ischaemic stroke</p> <p>§ G46: not a diagnostic code; may be used for the presenting symptoms of either stroke or TIA.</p></div

Selection of studies.

<p><b>*</b>Additional studies identified from bibliography screening. †Additional studies identified from review articles and bibliography screening.</p

Effect on PPV of codes used to identify ischaemic stroke: within-study comparisons^*.

<p>*If there was more than one result per code, results are shown for the largest number of cases assessed.</p><p>^<b>†</b>Mean PPV taken from range of values in original publication.</p><p>Effect on PPV of codes used to identify ischaemic stroke: within-study comparisons^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140533#t002fn001" target="_blank">*</a>}.</p

Clinical characteristics of included studies in white populations.^*

<p>Clinical characteristics of included studies in white populations.^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0151743#t002fn001" target="_blank">*</a>}</p

Pooled prevalence of risk factors in Chinese and white intracerebral hemorrhage.

<p>ICH = intracerebral hemorrhage; CI = confidence interval; Betw group het = between-group (ethnic) heterogeneity; C = Chinese; W = Whites; HTN = hypertension; DM = diabetes; AF = atrial fibrillation; IHD = ischemic heart disease; HC = hypercholesterolemia. Horizontal lines represent 95% CIs. Diamonds represent pooled proportions.</p