Neurology -- Correspondence for Goldstein et al., 61 (6) 792-796

Correspondence published:

VA Stroke Study: Neurologist care is associated with increased testing but improved outcomes: Eric M Cheng, MD, MS, Gretchen Birbeck, Barbara Vickrey (3 December 2003)

Reply to Cheng et al: Larry B. Goldstein, David B. Matchar, Jennifer Hoff-Lindquist, Gregory P. Samsa, Ronnie D. Horner (3 December 2003)

VA Stroke Study: Neurologist care is associated with increased testing but improved outcomes 3 December 2003

Eric M Cheng, MD, MS,
Greater Los Angeles VA Healthcare System
11301 Wilshire Blvd; B500, ML 127; Dept of Neurology; Los Angeles, CA 90073,
Gretchen Birbeck, Barbara Vickrey
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Re: VA Stroke Study: Neurologist care is associated with increased testing but improved outcomes

eric.cheng{at}med.va.gov Eric M Cheng, MD, MS, et al.

We read with interest the article by Goldstein et al [1] that reported twice the rate of deterioration in the first 24 hours, and worse discharge functional status and mortality rates among acute stroke patients cared for by non-neurologists compared to those having neurologist attendings. These findings, based on a prospective, observational study conducted at nine VA hospitals, are carefully reported as associations, not causal.
Though the investigators adjusted for stroke severity (via Canadian Neurologic Scale) and comorbidity, the potential for confounding due to other, unmeasured prognostic characteristics remains high. At the West Los Angeles VA Hospital, assignment of stroke patients to inpatient neurology service vs. inpatient “non-neurology” service is not random and is highly influenced by the patients’ clinical state and perceived acuity. Stroke patients deemed by the neurology service to have a high risk for deterioration - such as those with stroke onset less than 72 hours - are admitted to the inpatient medical intensive care service for access to resources (i.e. 24-hour cardiac monitoring, nursing staff who can perform frequent neurological assessments, residents who are in-house overnight) that are not available on the inpatient neurology service. Therefore, we would expect higher rates of deterioration and worse outcomes among patients cared for on a non-neurology service at this VA hospital. This would not be due to differences in quality of care, but to local triage policy, itself driven by acuity (a characteristic not measured on the Canadian Neurologic Scale). [2]
There may be other kinds of local hospital policies regarding admission triage elsewhere, for example, policies that patients presenting over a weekend be admitted to a medicine service. Weekend admissions have been associated with increased mortality. [3]
The investigators also found differences in use of some diagnostic tests and treatments. Additional data could help discern whether such differences either explain or result from differences in outcomes. For example, higher rates of speech therapy in the neurologist group might have resulted from their better prognosis and hospital course, or – if speech therapy was a venue for a swallowing evaluation early in the hospitalization - it might have resulted in lower rates of aspiration pneumonia. Information on the timing of this evaluation and on rates of aspiration pneumonia would be useful. Data regarding blood pressure management in the first 24 hours could also help explain early deterioration and link outcome differences across groups to process measures of quality of care. [4]
References
1. Goldstein LB, Matchar DB, Hoff-Lindquist J, Samsa GP, Horner RD. VA Stroke Study: Neurologist care is associated with increased testing but improved outcomes. Neurology 2003; 61:792-796.
2. Cote R, Battista RN, Wolfson C, Boucher J, Adam J, Hachinski V. The Canadian Neurological Scale: validation and reliability assessment. Neurology 1989; 39:638-643.
3. Bell CM, Redelmeier DA. Mortality among patients admitted to hospitals on weekends as compared with weekdays. N Engl J Med 2001; 345:663-668.
4. Oliveira-Filho J, Silva SCS, Trabuco CC, Pedreira BB, Sousa EU, Bacellar A. Detrimental effect of blood pressure reduction in the first 24 hours of acute stroke onset. Neurology 2003; 61:1047-1051.

Reply to Cheng et al 3 December 2003

Larry B. Goldstein,
Durham VAMC & Duke University
Box 3651-DUMC, Durham, NC 27710,
David B. Matchar, Jennifer Hoff-Lindquist, Gregory P. Samsa, Ronnie D. Horner
Send Correspondence to journal:
Re: Reply to Cheng et al

golds004{at}mc.duke.edu Larry B. Goldstein, et al.

We thank Drs. Cheng, Birbeck and Vickrey for their comments. We carefully pointed out in the Discussion section of our report that VASt was an observational cohort study, and that factors underlying the observed differences can only be partially inferred based on the data that was collected. The potential for confounding due to unmeasured factors is inherent in all studies of this type.
However, we feel that biases based on acuity or weekend hospital admissions are unlikely. Although the difference was not significant, patients primarily cared for by a neurologist had slightly greater acuity than those cared for by non- neurologists (mean+/-S.E.M time from symptom onset to admission= 1.2+/-0.1 days for neurologists vs. 1.5+/-0.2 days for non-neurologists, Wilcoxon test, p=0.42). Although there were differences in the levels of organization of stroke care among the sites, there was no difference in outcome when sites with or without a stroke unit or stroke team were compared.
Further, stroke severity, the most important predictor of outcome, was virtually identical between patients primarily cared for by neurologists and those cared for by non-neurologists. Unfortunately, we do not have specific data to address the other points raised, but any causal interpretations would be subject to the same limitations pointed out by Cheng et al. Hypothesis-driven data collection is required to directly address these issues. Despite its limitations, the study is consistent with previous work suggesting a benefit of specialist care. Additional studies are needed to determine why stroke patients primarily cared for by neurologists have better outcomes.