Health outcomes 1 year after subarachnoid hemorrhage

Methods.

We used published methods of case ascertainment.6 In brief, 432 first-ever cases of SAH (mean age 56 years, range 16 to 94) in four Australasian centers (Adelaide, Hobart, and Perth, Australia; Auckland, New Zealand; total population 2.8 million ≥ 15 years) were registered between November 1995 and June 1998 using standard diagnostic criteria and uniform community-wide surveillance systems. SAH was defined as an abrupt onset of severe headache or loss of consciousness with or without focal neurologic signs and with CT (90%) or necropsy (10%) that showed focal or generalized subarachnoid blood.7 Patients whose hemorrhage was found definitely to originate from sources other than an intracranial aneurysm—including primary intracerebral hemorrhage, arteriovenous malformations, trauma, infections, bleeding diathesis, and neoplasms—were excluded, but those in whom an aneurysm could not be identified by CT or angiography or at necropsy were included (24%). There were 13 cases with a perimesencephalic pattern of hemorrhage on CT and normal four-vessel angiography8 and three patients with typical acute severe headache who died within a few hours of onset and before investigations could be organized. Case finding was staggered across centers, but averaged 2 years for Australian centers and 12 months for Auckland.

Trained research nurses in each center undertook face-to-face structured interviews with all cases (or proxies) as soon as possible after notification. For patients who had died or were disabled, the interview was conducted with a close relative, caregiver, or other reliable informant. Information obtained at baseline included demographics, living arrangements, and employment status. History of hypertension, diabetes mellitus, and cardiac disease (myocardial infarction or angina), and need for assistance in self-care activities of daily living (ADL), was determined by self-report. Data related to hospital care and management were extracted from medical records. Severity of disability at presentation was graded according to the Hunt and Hess system9 of five categories: Grade 1 (asymptomatic or mild headache, mild neck stiffness), Grade 2 (moderate to severe headache, neck stiffness, no neurologic deficit except cranial nerve palsy), Grade 3 (drowsiness, confusion, or mild neurologic deficit), Grade 4 (stupor or mild to moderate hemiparesis, possible early decerebrate rigidity and vegetative state), and Grade 5 (deep coma, decerebrate rigidity, moribund).

All patients not known to have died were contacted again approximately 1 year (mean time 1.2 years, hereafter referred to as follow-up) after the onset of SAH and invited to participate in the follow-up study. Those who agreed were asked, over the telephone, a series of simple yes/no questions relating to any problems with memory, mood, and speech. They were also asked about their living situation, employment status, and use of health care resources over the previous year, and their current health status. Then, they were asked two modified versions of the International Stroke Trial Collaboration simple questions10,11⇓: “Do you feel that you have made a full recovery from your subarachnoid hemorrhage?” and “Do you require help from anyone for everyday activities?” Finally, patients were administered the acute version of the 36-item short-form questionnaire (SF-36),12 which assesses HRQoL over the last week. The acute SF-36 was chosen to reduce the potential for recall bias arising from the assessment of patients with memory problems.

The SF-36 assesses HRQoL across eight health domains: physical functioning (PF), role limitations due to physical problems (RP), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), role limitations due to emotional problems (RE), and mental health (MH). Scores of 100 for PF, RP, BP, SF, and RE domains, and scores of 50 in the three remaining domains (GH, VT, and MH), indicate an absence of problems in those areas. For example, a score of 100 in PF indicates an ability to perform all activities without limitations due to ill health; a score of 50 in MH indicates an ability to function without personal or emotional problems. To obtain scores over 50 for GH, VT, and MH, health must be evaluated positively. For example, a score of 100 in MH indicates that the respondent “feels peaceful, happy and calm all of the time.”12 The SF-36 has been validated for use among people with stroke,13,14⇓ and is considered suitable for administration over the telephone.15-17⇓⇓ The study was approved by the relevant institutional ethics committees in each center and all patients (or their proxies) provided informed consent.

χ² Tests using Yates correction were undertaken on summary statistics, grouped by demographic and other characteristics, to compare proportions. SF-36 domain scores were calculated according to accepted guidelines.12 The Australian SF-36 population norms18 were standardized for age and sex to the frequency distribution in the study population. Forward step-wise logistic regression was used to determine baseline predictors of “complete” recovery. All data were analyzed using SAS version 6.12 (Cary, NC) for Windows19 and reported with 95% confidence intervals (CI) where appropriate.

Results.

Of the 432 cases of first-ever SAH registered in the study, 242 (56%) were alive at follow-up. Interviews were conducted with 230 (95%) of these patients. All patients were accounted for during follow-up, but information on health was missing for 12 patients, all late notifications from Perth. Nonparticipants did not differ from participants across baseline variables (data not presented). The mean time to follow-up was 1.2 years (range 0.4 to 3.1 years) after the onset of SAH; this figure includes 10 patients who were interviewed early due to logistical issues and 25 who were interviewed late due to delayed notification. Therefore, most patients—195 (85%)—were interviewed 12 to 18 months after onset of SAH. Most patients (75%) were from Australian centers: 80 (35%) in Adelaide, 26 (11%) in Hobart, 66 (29%) in Perth, and 58 (25%) in Auckland. Table 1 shows the baseline characteristics of these 230 survivors of SAH, stratified by their self-reported recovery status (complete versus incomplete recovery). Recovery data were missing for 19 patients (8%). Most patients were female, married, and the mean age was 50.9 years (range 16 to 93 years).

At follow-up, most patients lived with their family and reported independence in ADL; only 10 (4%) required institutional care. Of the 23 (10%) patients who reported being dependent in ADL at follow-up, four were dependent before the SAH. Table 2 shows that of 122 patients who were in waged full- or part-time employment before the SAH, two-thirds (80) had returned to this position 1 year later, after an average of 20 weeks away from work.

Overall, 106 (46%) patients stated that they had not recovered completely from the SAH, although 141 (61%) reported one or more impairments in memory, speech, mood, or physical function (i.e., dependence in ADL). Disturbances of memory (50%) and mood (39%) were common (figure 1), with 62 (27%) patients reporting impairments (or dependence) in only one of the four specific areas.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1. Self-reported health problems after subarachnoid hemorrhage, by self-reported recovery status.

HRQoL data were available for 174 (76%) patients and 15 (7%) proxies. Data from proxies were excluded from analysis due to small numbers and potential responder bias. Exploratory analysis revealed a trend for SF-36 scores to be lower as age increased, for females, and for the Australian population (data not shown). Patients scored significantly less than standardized Australian norms in RP (figure 2). Patients who stated that they had completely recovered from the SAH had significantly higher scores across all eight domains of the SF-36 compared with those who had an incomplete recovery, as outlined in table 3. The greatest differences between these two patient groups were in RP and RE. Using self-reported recovery status as a binary variable, we were unable to detect any baseline patient or disease characteristics that predicted (complete, self-reported) recovery after SAH.

• Download figure
• Open in new tab
• Download powerpoint

Figure 2. Difference between cases and Australian norm standardized Short Form–36 mean scores with 95% CI. PF = physical functioning; RP = role limitations due to physical problems; BP = bodily pain; GH = general health; VT = vitality; SF = social functioning; RE = role limitations due to emotional problems; MH = mental health.

Discussion.

Our results, from a population-based series, indicate that many patients who survive SAH continue to experience significant reductions in HRQoL, particularly in their ability to perform their social role. Between one third and one half of our patients reported problems in memory or mood and incomplete recovery from SAH at 1 year after onset. We were unable to determine any baseline patient or disease characteristics that predicted full recovery.

The strengths of this study are the large and well-defined study population, the completeness of follow-up, and the use of self-report measures of recovery, which included the well-validated SF-36. Previous research has often excluded the very old2,20⇓ and those with severe grades of SAH.21 Other studies have been undertaken in rehabilitation or neurosurgical settings,22-24⇓⇓ and sample sizes are often small.23,25,26⇓⇓ By minimizing selection and measurement bias, our data are broadly applicable to the wider population of patients with SAH.

Although SAH is associated with high early case fatality,27-32⇓⇓⇓⇓⇓ it is not generally regarded as a chronic disabling illness. Many believe that patients who have had an uncomplicated recovery, often with surgery, can expect to return to premorbid levels of functioning.2 Recent studies have highlighted discrepancies in objective assessment of neurologic outcome following SAH. Many patients with SAH who have had a “good outcome” as determined by a neurologist also have high level deficits in memory and other cognitive functions identified on neuropsychological examination.3 In our study, as well as others, over 50% of survivors of SAH reported problems with memory, mood, or neuropsychological function in the medium to long term.5,11,24-26,33⇓⇓⇓⇓⇓

Despite this literature, there is uncertainty about how these high level impairments might impact on the everyday lives of patients and their families. Our data indicate that ongoing problems in memory, mood, and possibly speech translate into disability in terms of social roles; that is, behavior that is expected of one’s self or of others that may include varying levels of responsibility. A role may be formal, such as doctor, or informal, such as sister or parent. The impact of physical or emotional problems on an individual’s ability to perform his or her social role can be assessed using the RP and RE domains of the SF-36.

In this study, patients who reported incomplete recovery from SAH (most of whom also reported problems in memory, mood, and speech) experienced significant reductions in HRQoL when compared with those who reported complete recovery. The largest differences in HRQoL occurred in the role domains of the SF-36. These findings are similar to those of Hop et al.,11 who found that patients with SAH who reported residual handicap scored significantly worse than those without handicap in the role and SF domains of the SF-36.

Recovery status at follow-up could not be predicted from the clinical severity or type of SAH, or whether the patient had early, late, or no surgery. These variables were evenly distributed between those reporting complete and incomplete recovery, indicating that the potential benefits of modern treatments could not be detected in this study.

Despite our study including a wide spectrum of patients with SAH, including the very old and those with the most severe clinical grades of SAH, our patients reported fewer problems than many other studies of this patient group. These studies found that less than half of patients were able to return to work after SAH,3,25,26⇓⇓ whereas we found that two thirds of previously employed people had returned to waged employment 1 year after SAH. Furthermore, only 10% of patients in our study were dependent in ADL, compared with up to 50% in other series.25 We acknowledge limitations in our data related to recall bias and measurement error, but these are unlikely to affect responses regarding well-defined outcomes such as dependence in ADL (i.e., physical disability) or return to employment.

One limitation of our data was the use of the acute version of the SF-36, particularly as Australian norms were derived from the standard version, which gives a 4-week frame of reference for responses. Proxy responses were also excluded from analysis of the SF-36, which potentially biases our results in a positive direction. Moreover, as there are no published Australasian norms available for the SF-36, use of the Australian norms provided a conservative comparison group (New Zealand norms are statistically higher across all SF-36 domains). However, we believe that these limitations would not significantly affect our results.

Appendix

Committee members, principal investigators, and study coordinators of ACROSS: Steering Committee: C. Anderson (Study Chair), N. Anderson, R. Bonita, D. Dunbabin, G. Hankey, K. Jamrozik. Data Management and Statistics: D. Bennett, J. Duncan, S. Vanderhoorn. Study Coordinators: J. Bennett (Study Manager), D. Healy, S. Rubenach (Adelaide); J. Sansom and J. Flecker (Hobart); J. Harvey, J. Linto, G. Mann, K. White (Perth); and S. Hawkins and C. Mulholland (Auckland). Neurosurgical Investigators: B. Brophy (Flinders Medical Center), J. Liddell (Royal Hobart Hospital), E. Mee (Auckland Hospital), G. McCulloch (Queen Elizabeth Hospital), N. Knuckey (Sir Charles Gairdner Hospital), and P. Reilly (Royal Adelaide Hospital). Clinical Centers: Ashford Hospital, Flinders Medical Center, Memorial Hospital, Repatriation General Hospital, Queen Elizabeth Hospital, and the Royal Adelaide Hospital (Adelaide, South Australia); the Royal Hobart Hospital, Calvary Hospital and St Helen’s Private Hospital (Hobart, Tasmania); Fremantle Hospital, Royal Perth Hospital, St John of God Hospitals, and Sir Charles Gardner Hospital (Perth, Western Australia); Auckland Hospital, North Shore Hospital, Middlemore Hospital, and Waitakare Hospital (Auckland, New Zealand).