Doctor of Health Sciences / A common and clinically important complication of late stage human immunodeficiency virus Type 1 (HIV-1) infection is HIV-associated neurocognitive disorder (HAND). HAND encompasses three syndromes, HIV-associated asymptomatic neurocognitive impairment (ANI), HIV-1- associated mild neurocognitive disorder (MND), and HIV-1-associated dementia (HAD). It is estimated that 30-60% of all HIV-1 infected individuals will have at least mild neurocognitive impairment (MND), and 10-15% of those will develop HAD. Research conducted outside medicine has focused on identifying the type and pattern of neuropsychological impairments present in people with HAND, and to correlate impairments identified from neuropsychological testing with scores on laboratory-based tests of everyday task performance. Typically, the performance of tasks and routines in daily life occurs in naturalistic contexts, and is orchestrated around the achievement of personally meaningful, needed and/or desired performance goals. It requires that one uses cognitive strategies to attend, perceive, remember, decide, plan and act on intentions within real-world contexts. Little is known about the impact of cognitive information processing strategy application impairments on the performance of meaningful tasks and routines carried out by people with HAND in contexts where performance would naturally occur. This research addressed this gap by investigating the real-world impact of information strategy application disorder in a sample of 30 men diagnosed with HAD, the most severe form of HAND. The home contexts of those in the sample consisted of home, supported living and residential care. The criterion-referenced Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis was used to identify the level of task performance mastery demonstrated by men in the sample (Stage One), and the information processing strategy application errors that impacted on their performances (Stage Two). The Clinical Staging of AIDS Dementia Complex (CSADC) scale was used to identify the level of severity of HAD. A total of seventy one task performances were assessed across the sample in a variety of naturalistic contexts. None of the men in the sample demonstrated mastery of task performance. The mean Mastery score was 30.07%. The predominant type of error made by men as they performed daily life tasks was Timing; they spent too much time completing tasks. This was followed by errors of Accuracy; they made mistakes in what they did. Descriptive analysis of the PRPP Stage Two scores revealed that these men had difficulties across all domains of information processing strategy application but most notably with Plan Quadrant (Mean 30.75%) and Perceive Quadrant (Mean 53.49%) strategy application behaviours. Rasch calibration of the ordinal PRPP Stage Two strategy application scores produced an interval-level linear hierarchy of information processing strategy application difficulties experienced by the group. Men in the sample demonstrated problems sequencing complex tasks, choosing plans and actions, analysing problems encountered, and monitoring sensory changes during performances. Problems were also identified in their abilities to contextualise their performances to fit within time constraints (Contextualises to Duration), and enact plans in a fluid manner (Flows). Differences in performances between men with mild dementia versus those with moderate/severe dementia identified using a 2 x 4 repeated measures ANOVA carried out on the Rasch-calibrated PRPP Stage Two scores revealed similarities in performance across Perceive, Recall, Plan and Perform Quadrants but those with mild dementia performed better overall. Further analyses revealed specific differences in performance between those with mild versus those with moderate/severe dementia. Most striking about the findings was that men at both ends of the dementia spectrum had relatively good Recall Quadrant strategy application capacities (Mean 75.30%). Even those with the lowest total PRPP Stage Two scores, could recognize and use objects, and recall the procedures of known tasks. A statistically significant predictive correlation was found between Plan Quadrant disorders and severity of dementia. This pilot study demonstrated the utility of the PRPP System, a criterion-referenced, occupation-embedded, ecological method of identifying task performance skill and information processing strategy application disorders impacting on performance, for use with people living with HIV/AIDS who have HAD. Identifying the specific impact of information processing strategy application disorders on real-world task performance provides occupational therapists with information necessary to more specifically tailor therapy to the individual performance and participation needs of people with HIV-1-associated dementia.
Identifer | oai:union.ndltd.org:ADTP/290291 |
Date | January 2010 |
Creators | Ranka, Judy L. |
Publisher | University of Sydney. |
Source Sets | Australiasian Digital Theses Program |
Detected Language | English |
Rights | The author retains copyright of this thesis., http://www.library.usyd.edu.au/copyright.html |
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