Table 2.
Summary of Included Studies
| Study | Location | Setting | No. Patients |
Mean age* |
Inclusion Criteria |
Study Design | SAH Criterion Standard |
SAH prevalence % |
Variables Assessed |
Follow- Up |
|---|---|---|---|---|---|---|---|---|---|---|
| Backes 2012 | University Medical Center, Utrecht, Netherlands, 2005-2012 |
ED | 250 | 48* | Age >16 years, clinical suspicion of acute onset SAH, GCS 15 |
Two prospective databases. First database consecutive patients with confirmed SAH. Second all LP patients with SPT |
Not explicitly defined |
42.0 | Sen/Spec CT at <6- hours and >6-hours for SAH |
None |
| Bo 2008 | Akershus University Hospital, Norway, 1998-2002 |
ED | 433 | 44 | Age >14 years, acute onset worst headache of life |
Prospective observational consecutive sampling cohort |
Consensus between two neurologists, but not explicitly defined |
16.4 | Sen/Spec of elements of history including activity at onset, and peak intensity for SAH |
None |
| Boesiger 2005 |
Pitt County Memorial Hospital, Greenville SC, 2002 |
ED | 177 | NR | Adults with headache work-up including CT and LP |
Retrospective chart review |
SAH observed on CT or ≥400 RBC in CSF tube 1 that did not clear by 10-fold |
3.4 | Sen/Spec of CT for SAH |
Phone f/u at 1-year if ≥400 RBC in CSF tube 1 that did not clear by 10-fold |
| Brunell 2013 |
Uppsala University Hospital, Uppsala Sweden, 2009-2011 |
Hospit al |
453 | NR | Age>10 years with LP to exclude SAH |
Lab information system review |
CSF hemoglobin detection via SPT using 415 nm wavelength or CSF bilirubin detection via automatic analyzer |
1.1 | Sen/spec of CSF RBC for SAH |
None |
| Carstairs 2006 |
Naval Medical Center San Diego CA, July 2002-July 2004 |
ED | 116 | 39 | Age>18 with either worst headache of life or onset <60 seconds or associated neuro deficit |
Prospective observational consecutive sampling cohort |
SAH observed on CT or RBC in CSF tube 1 that did not clear by >25% in tube 4 or presence of xanthochromi a on visual inspection by lab |
4.3 | Sen/Spec of CTA & elements of history including stiff neck, blurred vision, & altered mental status |
None |
| Czuczman 2013 |
Unspecified urban tertiary care hospital, 2001-2009 |
ED | 220 | 44 | Adults with headaches billed for LPs, ≥5 RBC in final CSF tube, and either CT angiogram or magnetic resonance angiogram within 2- weeks |
Retrospective case series |
Either 1) presence of SAH on imaging; 2) xanthochromi a with aneurysm or AVM>2mm; 3) xanthochromi a and culture- or PCR- negative meningitis |
11.8 | Sen/Spec of elements of history including sudden onset headache, worst headache, & onset with exertion; CSF RBC iLRs |
None |
| Dupont 2008 |
St. Mary’s Hospital, Rochester MN, 1998- 2007 |
ED | 117 | 45 | Age>18 with headache onset <2 weeks prior with both non-contrast CT for detection of blood and LP |
Retrospective chart review |
Not specified | 12.0 | Sen/Spec visual xanthochr omia for aneurysm |
None |
| Gangloff 2015 |
Hôpital de l’Enfant-Jésus, Quebec Canada, 2003- 2009 |
ED | 706 | 41 | Age>14 with acute headache suspicious for SAH, GCS 15, and initial head CT negative for SAH with subsequent LP |
Retrospective case series |
Presence of any aneurysm and presence of either visual xantho or >5 × 106 RBC/L in last CSF tube |
0.7 | Sen/Spec visual xantho, iterative SPT, or UK NEQUA SPT |
None |
| Hann 2015 | Royal Brisbane & Women’s Hospital, June 2005-July 2012 |
ED | 409 | 38 | Adults discharged with headache after CSF evaluation for xantho |
Retrospective case series |
Presence of vascular aneurysm on angiogram within 30- days of headache or no repeat ED visit or SAH death in 30- days |
1.5 | Sen/Spec visual xantho via visual inspection |
Review of Queensland death registry |
| Landtblom 2002 |
University Hospital, Linköping Sweden over unspecified 31-month period |
ED | 137 | 42* | Age>18 years presenting within 10 days of headache onset with abrupt onset (<10 second) headache, examined by on-call Neurologist |
Prospective observational cohort |
Not specified | 11.3 | Sen/Spec of elements of history including sudden onset headache, worst headache, & nausea |
Phone at 2-4 days, 7-9 days, and 1-, 3-, 6-, and 12- months for 90 subjects without SAH |
| Linn 1998 | Utrecht University Hospital, Utrecht, Netherlands, Jan 1992-Oct 1994 |
ED | 102 | 48 | Alert adult patients without focal neuro deficit referred to ED by general practitioner with concern for SAH with CT and LP |
Prospective observational cohort |
Not specified | 41.2 | Sen/Spec of elements of history including activity at onset and acuity of onset |
None |
| Morgenstern 1998 |
Hermann Hospital, Houston TX, March 1995- June 1996 |
ED | 97 | 39 | Adult patients with 10/10 worst headache of life |
Prospective observational cohort |
Either 1) presence of SAH on imaging OR 2) CSF RBC > 1000 with <25% decrement from first to last tube with either visual xantho, SPT xantho, or elevated D- dimer |
18.6 | Sen/Spec of elements of history & physical exam including nausea, stiff neck, and lethargy |
Phone f/u at mean 24 months |
| O’Neill 2005 | Unspecified hospital over unspecified 1- year period |
ED | 116 | NR | Acute headache <24 hours, clinical suspicion SAH, referred for CT from ED |
Retrospective chart review |
Not specified | 16.4 | Sen/Spec of CT for SAH |
None |
| Perry 2006 | 6 Canadian tertiary care EDs, July 2002-Jan 2004 |
ED | 220 | 42 | Age>15 years with acute, spontaneous headache with or without syncope |
Pre-planned sub- study of prospective, consecutive patient cohort study |
Any one of the following: subarachnoid blood on CT, >5×106/L RBC in 3rd or 4th tube of CSF, or visible xantho + aneurysm on cerebral angiography |
0.9 | Sen/Spec of visual inspection for xanth and 4 SPT methods for xantho for SAH |
Phone f/u at 1- month for CT-, LP- patients; chart review at 1-month for all patients |
| Perry 2010 | 6 Canadian tertiary care EDs, Nov 2000-Nov 2005 |
ED | 1999 | 43 | Age≥16 years with spontaneous headache peaking within 1- hour or syncope associated with a headache |
Prospective cohort study |
Any one of the following: subarachnoid blood on CT, visual xantho, >5×106/L RBC in the final tube of CSF with an aneurysm or AVM on cerebral angiography |
6.5 | Sen/Spec of elements of history including activity at onset, neck stiffness, and arrival mode. Also, derivation of 3 CDRs |
Phone f/u at 1- and 6-months for all patients without CT or LP; chart review & Ontario registry review at study end for same patients |
| Perry 2011 | 11 Canadian tertiary care EDs, Nov 2000-Dec 2009 |
ED | 3132 | 45 | Age>15 years with acute, spontaneous headache with or without syncope |
Prospective cohort study |
Any one of the following: subarachnoid blood on CT, visual xantho, >5×106/L RBC in the final tube of CSF with an aneurysm or AVM on cerebral angiography |
7.7 | Sen/Spec CT at <6- hours and >6-hours for SAH |
Phone f/u at 1- and 6-months for all patients without CT or LP; chart review & provincial coroner’s records at study end for same patients |
| Perry 2013 | 10 Canadian tertiary care EDs, Nov 2000-Dec 2009 |
ED | 2131 | 44 | Age≥16 years with spontaneous headache peaking within 1- hour or syncope associated with a headache |
Prospective cohort study |
Any one of the following: subarachnoid blood on CT, visual xantho, >5×106/L RBC in the final tube of CSF with an aneurysm or AVM on cerebral angiography |
6.2 | Sen/Spec of elements of history & physical exam including activity at onset, neck stiffness, and arrival mode. Also, derivation of 4 SAH CDRs |
Phone f/u at 1- and 6-months for all patients without CT or LP; chart review & provincial coroner’s records at study end for same patients |
| Perry 2015 | 12 Canadian tertiary care EDs, April 2006-July 2010 |
ED | 1739 1098 normal LP 641 abnl LP |
44 | Age>15 years with acute, spontaneous headache with or without syncope with LP to evaluate potential SAH |
Pre-planned sub- study of prospective, consecutive patient cohort study |
Aneurysmal SAH if: subarachnoid blood on CT, visual xantho,or any RBC in the final tube of CSF with an aneurysm on cerebral angiography |
2.3 | Sen/Spec of <2000 × 106/L RBC in CSF + no xantho for diagnosis aneurysmal SAH |
Phone f/u at 1- and 6-months for all patients without CT or LP; chart review & provincial coroner’s records at study end for same patients |
| Van der Wee 1995 |
University hospitals in Utrecht and Rotterdam Netherlands, 1989-1993 |
NR | 175 | NR | Acute headache without confusion or focal deficit with CT within 12- hours |
Unclear whether retrospective or prospective “consecutive” case series |
Not specified | 68 | Sen/Spec CT at <12- hours for SAH |
None |
| Wood 2015 | Princess Alexandra Hospital, Brisbane Queensland Australia, Jan 2000-April 2003 |
NR | 240 | NR | Acute or unusually severe headache with LP after a normal cranial CT for possible diagnosis of SAH |
Retrospective chart review |
Uniform CSF bloodstaining across serial samples with visual xantho and “positive” angiography |
0.8 | Sen/Spec of CSF SPT (XI > 0.080) |
None |
*
Median
Abbreviations: ED = emergency department, SAH = subarachnoid hemorrhage, GCS = Glasgow Coma Scale, sen = sensitivity, spec = specificity, CT = computed tomography, f/u = follow-up, RBC = red blood cell, CTA = CT angiogram, AVM = arteriovenous malformation, LP = lumbar puncture, CSF = cerebrospinal fluid, iLR = interval likelihood ratio, UKNEQUASPT = United Kingdom National External Quality Assessment Service photochromatography, xantho = xanthochromia, CDR = clinical decision rule