Risk Factors of van de Beek et al for an Unfavorable Outcome After Community-Acquired Bacterial Meningitis

 

Outcomes were classified as unfavorable if the Glasgow Outcome Scale was 1 to 4 (death to moderate disability) and favorable if 5 (no to mild disability).

 

Isolates included Streptococcus pneumoniae, Neisseria meningitidis, Staphylococcus aureus, Listeria monocytogenes, Haemophilus influenzae and "others:.

 

Parameters:

(1) age

(2) otitis

(3) sinusitis

(4) rash

(5) admission Glasgow coma scale (GCS)

(6) heart rate

(7) blood culture

(8) erythrocyte sedimentation rate (ESR)

(9) platelet count

(10) CSF fluid WBC count

 

Parameter	Finding	Points
age of the patient	< 60 years of age	0
	>= 60 years of age	1
otitis	absent	0
	present	1
sinusitis	absent	0
	present	1
skin rash	present	0
	absent	1
admission Glasgow Coma Scale	12 - 15	0
	<= 11	1
heart rate	< 120 beats per minute	0
	>= 120 beats per minute	1
blood culture	negative	0
	positive	1
ESR	< 56 mm in first hour	0
	>= 56 mm in first hour	1
platelet count	>= 110,000 per µL	0
	< 110,000 per µL	1
CSF WBC count	>= 1,000 per µL	0
	< 1.000 per µL	1

 

where:

• The table reports that survivors had a mean GCS of 10 and nonsurvivors of 12, which seems the opposite of the text. The ranges were 7 to 13 and 9 to 15.

• The mean for the favorable platelet count was 208,000 per µL and 180,000 per µL. The distributions overlap except for 83,000 - 108,000.

• The ESR for favorables was 5 to 79 mm/h and unfavorables was 19 to 93, so there was considerable overlap. I used the mean of the unfavorable range for the implementation.

• The age distribution was 25 to 65 for favorable outcomes and 42 to 78 for unfavorable. I used the mean of the unfavorable range for the implementation.

 

total number of risk factors =

= SUM(points for all 10 risk factors)

 

Interpretation:

• minimum number of risk factors: 0

• maximum number of risk factors: 10

• The more risk factors present the greater the risk.

 

Additional factors associated with an unfavorable outcome:

(1) Streptococcus pneumoniae as pathogen (30% mortality rate)

(2) presence of symptoms < 24 hours on admission

(3) seizures

(4) pneumonia (? marker for Streptococcal pneumoniae)

(5) immunocompromised state (immunosuppressive drugs, history of splenectomy, diabetes mellitus, alcoholism, HIV infection; I would also add primary immundeficiency states and lymphoproliferative disorders)

(6) hypotension with diastolic blood pressure < 60 mm Hg

(7) heart rate < 60 beats per minute