Development and validation of the stroke knowledge test.(Grand Rounds)

Purpose: The purpose of this study was to develop a measure of stroke knowledge (the Stroke Knowledge Test [SKT]) using a systematic test construction process and to investigate the psychometric properties of this test. There are relatively few published measures of stroke knowledge, and, of those that exist, relatively little is documented about test construction or psychometric properties. Such tests are important for evaluation of stroke education programs. Method: Test construction involved systematic generation of pilot test items, expert review of pilot items, and calculation of pilot item properties. After final item selection, two experiments were conducted to determine if the SKT was sensitive to varying levels of stroke knowledge and to estimate the reliability of the test. Results: The final version of the test included 20 items with good content coverage, acceptable item properties, and positive expert review ratings. Results from psychometric investigations suggest that SKT has relatively good reliability (internal consistency and test-retest reliability) and construct validity (i.e., SKT scores significantly increased after stroke education [cf. nonstroke education], and community-dwelling older adults who had a relative with stroke [and more prior exposure to stroke information] scored higher on the SKT than those without a stroke relative). Conclusion: Findings provide preliminary support for the SKT as a valid and reliable tool for assessing stroke knowledge. The SKT may be used to identify individual information needs of stroke survivors and their caregivers or as a tool to evaluate group- or community-based stroke education programs. Key words: patient education, rehabilitation, stroke education, stroke knowledge

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Stroke affects more than 40,000 Australians annually and is the most common cause of disability in the elderly. (1-4) The effects of stroke are substantial and impact extensively upon the quality of life of both stroke survivors and caregivers. (5) Further, the prevalence of stroke is expected to increase with the aging of the population. (3)

Stroke is clearly a major public health issue; however it is important to note that the risk of stroke may be reduced by healthy lifestyle change and the extent of stroke-related disability may be minimized by early intervention and treatment. For example, early recognition of stroke symptoms is crucial for appropriate diagnosis and treatment. (6-8) Additionally, adherence to treatment recommendations may be improved by addressing some of the common misconceptions articulated by noncompliers, such as unwillingness to engage in gentle exercise because this is perceived as increasing stroke risk. (9)

Previous strategies used to improve awareness of stroke risk reduction factors and stroke knowledge in general have included public education programs, (3,10,11) stroke education tailored to patients' and carers' needs, (12) and group-based information programs. (8) In addition, a variety of media have been used to deliver stroke education programs, including video. (13) The general pattern of results from patient- and carer-based education studies suggests there are a number of benefits of providing stroke education, such as reduced carer burden (e.g., ref. 14; for an exception, see ref. 15). This general trend in patient education evaluation studies is consistent with findings in other areas that suggest illness knowledge is an important precursor to healthy lifestyle change in conditions such as diabetes (16) and cardiovascular disease. (17)

The precise nature and extent of the beneficial education effect found in patient and carer education studies is somewhat difficult to characterize given that there are a number of important methodological issues that complicate the interpretation of results from such studies. First, there is substantial variation in outcome measures used to define effective stroke education. That is, studies examining the efficacy of education interventions typically attribute change in behavior, such as a decrease in caret stress, to the effects of education without directly assessing change in understanding of stroke. Outcome measures have included the extent to which stroke-related education influences the stability of family functioning, (18) adherence to treatment recommendation, (19) reported anxiety, (20) perceived health status, (12) and level of satisfaction with health services. (21) The general findings from the majority of these studies have indicated that the provision of stroke education results in improvements on such measures (e.g., increased satisfaction with health services, (21) reduced anxiety, (20) more stable family functioning, (18) and consequently greater adherence with treatment recommendations (19)). Essentially then, stroke knowledge (which can be defined as patients or carers understanding of stroke) is implicated as the underlying mechanism associated with mediating such improvements.

Second, in the few studies in which change in stroke knowledge has been assessed directly as an outcome measure (either as the single outcome measure or in combination with one of the measures identified earlier [e.g., refs. 15, 20-22]), results have been complicated by the use of a range of different, relatively unstandardized outcome measures, including those with undocumented psychometric properties. Indeed, this has led to recognition of the absence of (and consequent need for) formal psychometric testing of stroke knowledge measures that could be used to accurately evaluate the efficacy of existing stroke education programs. (15,21)

The third factor that has complicated the interpretation of stroke education evaluations has been the failure to assess outcomes pre- and posteducation (15,18) or to include an appropriate control or comparison group. (19,23) In the absence of these design features, it is difficult to accurately determine the magnitude of …