Validation study findings showed that knowledge KR had moder
Validation study findings showed that knowledge (KR20=0.58) had moderate internal consistency. Even though this was fairly acceptable, the knowledge domain was considered a good test as KR20 tends to result in more conservative estimates than Cronbach’s alpha . Enhancing the reliability of a questionnaire can be done by increasing the number of items  and increasing the sample size might produce a different internal consistency result. KR-20 is a frequently used method for determining internal consistency if the items are dichotomously coded. Basically, the computation requires three pieces of information, namely the number of items, the mean, and the standard deviation.
The reliability of the SKT instrument was rated at moderate level for this preliminary study; however, according to Downing and Haladyna  and Sullivan and Dunton , this level of internal consistency is acceptable for a new instrument and should not be a barrier for its use. However, a larger scale study is needed to determine if there is a significant impact on the interpretation of internal consistency estimates for the instrument.
Researchers need to conduct test–retest reliability relevant for cognitive and trait scales not expected to change over time . The minimal requirement for conducting test–retest reliability was at least two weeks to six months. However, it d-amphetamine is not appropriate for states that were expected to change over time, such as attitude, mood, or knowledge following an intervention . Therefore, this study did not carry out test–retest reliability since researchers expected a change in the knowledge score over time during the intervention study. Furthermore, the short hospital stay among the stroke patients prevented the researchers from completing test–retest reliability measurements.
Conflict of interest
Acknowledgment Financial assistance for this study was provided by Universiti Sains Malaysia via Short Term Grant (304/PPSKB61313012).
Introduction Left atrial appendage (LAA) occlusion with the Watchman® device (Boston Scientific, Natick, USA) has demonstrated efficacy in long term stroke prevention for patients with non-valvular atrial fibrillation (AF) with a CHADS2 score ≥1 and a demonstrated mortality benefit compared with warfarin . Catheter ablation therapy for AF is an efficacious rhythm control strategy for patients with symptomatic, drug-refractory AF , but its role in long-term stroke prevention remains unproven. Evidence suggests clitoris longer term AF recurrence rates, following initially successful catheter ablation are significant , and that oral anticoagulation cannot be safely stopped in patients with a CHA2DS2-VASc stroke risk score of ≥2 . Both procedures require percutaneous catheter instrumentation of the left atrium. Therefore, a subset of patients with symptomatic AF may benefit from undergoing concomitant intervention of catheter ablation and device occlusion of the LAA  as a two-pronged strategy for rhythm control and stroke prevention. We report on the outcome of combined procedures with the Watchman® device in a single center over a 5-year timeframe.
Material and methods In December 2009, following Therapeutic Goods Administration approval of the Watchman® device in Australia, patients with a CHADS2 score of 1 or greater (PROTECT AF inclusion criteria ), seeking to undergo left atrial catheter ablation for symptomatic, drug-refractory non-valvular AF at a single center, were offered concomitant implant as an alternative to taking long-term oral anticoagulation. Subsequent to the updated ESC Clinical Guidelines for the Management of Atrial Fibrillation in 2010 , a CHA2DS2-VASc score of 2 or greater was used for eligibility. This retrospective study was approved by the institutional review board for human research and complies with the Declaration of Helsinki. Informed consent was obtained from all participants.