3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item The effect of a workplace intervention programme on return to work after stroke(2014-02-06) Ntsiea, Mokgobadibe VeronicaStroke impacts on a survivor’s ability to participate in community activities such as return to work (RTW) and affects people who are still within the working age. Return to work contributes to life satisfaction and social identity at least partly through independence gained from income-generation. The impact of RTW programmes for stroke survivors is limited and not generalisable to South Africa. This study aimed to bridge this gap in South Africa, and was conducted within the Gauteng province as it comprises the largest share of the South African population. Objectives and Methodology: The aim of the study was to determine the current practice in RTW intervention programmes for stroke survivors in the Gauteng Province of South Africa and to establish the effect of a workplace intervention programme on the rate of RTW of previously employed stroke survivors. This study had two stages: Stage one: A cross sectional survey was performed using a self administered questionnaire to establish current practice in RTW intervention programmes and the therapists’ perceived barriers and enablers of RTW after stroke. Stage two study included: a) a randomised controlled trial (RCT) to evaluate a six week RTW intervention, with follow-up at three and six months. The workplace intervention programme was tailored according to the functional ability and workplace challenges of each stroke survivor and was as follows: Week one: Assessment for work skill. The assessment included work modules which identified potential problems such as: visual discrimination; eye hand coordination; form and spatial perception; manual dexterity; colour discrimination; cognitive problems, and job specific physical demand factors. Week two: The therapist interviewed the stroke survivor and employer separately to establish perceived barriers and enablers of RTW. This was followed by a meeting between the therapist, stroke survivor and employer/supervisor to discuss and develop a plan to overcome identified barriers and to strengthen identified enablers based on consensus between stroke survivor and employer. Week three: A work visit for the stroke survivor to demonstrate what they did at work and identify what they could still do safely and what they could not do. This included vocational counselling and coaching; emotional support; adaptation of the working environment; advice on coping strategies to compensate for mobility and upper limb functional limitations; and fatigue management. Weeks four, five and six: continuation of the work visits, while monitoring progress, and making necessary adjustments as per stroke survivor and employer’s needs. This was done at the workplace while the participants continued with their usual therapy at the hospital. The control group received usual care. The primary outcome was RTW rate. The secondary outcomes included activities of daily living (measured with the Barthel Index); mobility (measured with the Modified Rivermead Mobility Index); basic cognitive function (measured with the Montreal Cognitive Assessment) and perceived quality of life (measured with the Stroke Specific Quality of life Scale). Another aim of stage two study was to: b) establish the stroke survivors’ and employers’ perceived barriers and enablers of RTW (this was done with the experimental group only); and to: c) identify predictors of RTW. Stage one study results: Thirty six (68%) of the 53 questionnaires sent to stroke rehabilitation facilities were returned. Seventeen (47%) of the 36 clinical settings referred stroke survivors to facilities offering RTW services; 12 (33%) facilities did not refer stroke survivors for RTW and did not offer RTW services; and seven (20%) facilities offered RTW services. Of the seven facilities that rendered RTW services for stroke survivors, five (71%) communicated with the employer to discuss reasonable accommodation and four (57%) did assessments for potential to RTW. The most common reason given by the 29 facilities for not offering RTW services was that they referred stroke survivors to other therapists who offered these services. The second most common reason was the unemployment status of the stroke survivor at the time of having stroke. The therapists’ most commonly perceived barriers of RTW were the severity of the stroke survivors’ physical impairments (n = 3) (36%) and their employment status (n = 11) (31%) at the time of having stroke. The most commonly perceived enablers were willingness of the employer to reasonably accommodate the stroke survivor at work (n = 12) (33%), family support (n = 8) (22%) and increased length of hospital stay to allow for intensive rehabilitation (n = 7) (19%). Stigma in the workplace was the only variable which had a statistically significant relationship with the type of clinical facility therapists worked at (p = 0.02). Stage two study results: The average age for the study group was 45 (SD: 8.7) years and the average stroke duration was 4.6 (SD: 1.8) weeks. There were 41 (51%) male stroke survivors and 39 (49%) female stroke survivors. Majority (55%) of the stroke survivors were breadwinners (63%), had a grade 11 to 12 educational level (64%), an income above R5000 (46%) and had a helper (74%) whom they did not have to pay (81%). Stroke survivors who returned to work had better quality of life at six months after stroke than those who did not RTW (p = 0.05). Results from the qualitative study indicated that the perceived enablers of RTW included: ability of the employer to provide reasonable accommodation and good interpersonal working relationships between stroke survivor, employer and co-workers. The perceived barriers of RTW included: unaffordable reasonable accommodation costs; inaccessible transport; having cognitive (memory and attention) and speech impairments and high unemployment rates. The overall RTW rate was 20% at three months follow-up and 40% at six months follow-up. Twenty seven percent of the stroke survivors in the intervention group returned to work at three months compared to 12% in the control group (p = 0.13). At six months, the majority of stroke survivors (60%) in the intervention group returned to work compared to 20% in the control group (p <0.001). The following factors were predictive of RTW: male gender (p = 0.03); fewer speech problems (p = 0.02); increased time off work post stroke (p = 0.001); ability to perform activities of daily living (p = 0.02); good mobility (p = 0.01) and good cognitive ability (p = 0.02). The stroke survivors in the intervention group were 5.2 times more likely to RTW than those in the control group at six months following stroke, and for every unit increase in the activities of the Barthel Index and Montreal Cognitive assessment score, the likelihood of RTW increased by 1.7 and 1.3 respectively. Conclusion: A RTW intervention consisting of workability assessments and workplace visits was effective in facilitating RTW for stroke survivors in Gauteng province, South Africa. Key predictors of RTW included male gender; increased time off work post stroke; ability to perform activities of daily living; good mobility and good cognitive ability and were identified as facilitating RTW; speech problems were identified as barriers to RTW. Overall, these results suggest the need to direct resources towards increasing work place intervention strategies after stroke.Item Physical abilities of community-dwelling adults more than six months post stroke: a cross sectional survey(2010-06-25T09:28:52Z) Dearle, Luschka AnneBackground and purpose of the study The length of stay for patients with stroke in some South African government hospitals has been shown to be inadequate and there is little information on the physical impairments and functional abilities of this population once they return to the community. An assessment was done of the strength, range of movement and the presence of pain experienced by patients with stroke in the Daveyton community and the relationship between these impairments and the functional abilities of these patients was established. Research methods and procedures employed This was a quantitative study using a descriptive cross sectional study design. Thirty-four conveniently sampled patients with stroke were assessed in their Daveyton homes. The functional measures used were the Modified rivermead mobility index (MRMI) and Barthel index (BI). The strength was assessed using a hand-held dynamometer, range of movement (RoM) with a standard universal goniometer and pain with the Eleven faces pain scale. The significance of the study was set at 0.05 and the relationships between impairments and functional abilities were expressed using the Spearman’s rank correlation coefficient. Results Significant differences were found between the strength, as well as the RoM of the affected and unaffected sides (p < 0.05). The muscles most affected by were: Biceps, Gastrocnemius and Tibialis Anterior. The smallest strength difference was found in Gluteus maximus. The ranges of movement most affected were: shoulder flexion and elbow extension. The smallest difference was found in knee extension. Eighty-five percent of the sample attained scores indicating that they were independently mobile (measured by the MRMI), and 82% were independent in activities of daily living (measured by the BI). There were good correlations between the patients’ strength impairments and their functional abilities (r = 0.54 to 0.79) and mobility (r = 0.51 to 0.76). Functional abilities and mobility had moderate to good relationships with active range of movement of shoulder flexion, lateral shoulder rotation and dorsiflexion. The percentage of patients experiencing pain was 73%, but pain displayed no relationship with functional ability (r = 0.14) and mobility (r = 0.15). Conclusion Most people living with stroke in the Daveyton community are functionally independent despite the high prevalence of pain. Stroke results in significant strength and active range of movement deficits on the affected side. Most strength impairments correlated well with the functional ability and mobility of this sample, but active range of movement impairments that influenced functional measures were mainly shoulder and ankle movements.Item PHYSICAL AND CHEMICAL PROPERTIES OF AEROSOL PARTICLES IN THE TROPOSPHERE: AN APPROACH FROM MICROSCOPY METHODS(2007-02-26T13:19:17Z) Gwaze, PatiencePhysical and chemical properties of atmospheric particles are fundamental but not necessarily easily accessible parameters. Uncertainties in these parameters are responsible for some uncertainties associated with radiative impacts of aerosol particles in global climate models. The uncertainties pertain to limitations of sampling and measurement devices, difficulties in modelling aerosols (source strengths, spatial and temporal variability) and in understanding microphysical and optical properties of aerosol particles. Physical and chemical properties can be obtained at single-particle level by microscopy analyses of individual particles. Using refined analytical and interpretative techniques to derive some of these fundamental properties, aerosol particles collected in various field campaigns and laboratory experiments were investigated using two high resolution microscopes. The particles were collected during the LBA-EUSTACH, Large-Scale Biosphere-Atmosphere Experiment part of European Studies on Trace Gases and Atmospheric Chemistry; SMOCC campaign, Smoke Aerosols, Clouds, Rainfall and Climate; CTBH II, Cape Town Brown Haze II campaign; and a controlled combustion experiment. Microscopy techniques were compared and complemented with conventional techniques to characterise particle sizes, shapes, chemical compositions and mixing states. Particle size distributions were compared between geometric equivalent sizes measured from microscopes and aerodynamic equivalent diameters, while taking into account particle densities. Large differences were found between the particle sizing techniques. Microscopy sizes (3D) were systematically lower than expected, and depended on the relative humidity during particle sampling. Differences were attributed to loss of mass, presumably water adsorbed on particles. Losses were high and could not be accounted for by known humidity growth factors suggesting losses of other volatile compounds adsorbed on particles as well. Findings suggest that there are inherent problems in defining particle sizes with different sizing techniques, despite accounting for humidity growth of particles and particle density. For collected particles, there are mass losses on individual particles, as opposed to particle losses to walls during sampling. These losses will inevitably bias observed mass distributions derived from collected particles and hence their number-size distributions. Relatively young aggregated soot particles from wood combustion were investigated for particle morphology (fractality, specific mass) and dynamic properties. Based on a procedure that has been validated on modelled aggregates, several important parameters to characterise geometry and drag-to-mass relationship of aggregates were derived. Three techniques were used to derive fractal dimension of soot aggregates. Averaged fractal dimension was found to be Df = 1.82 ± 0.08. Dynamic shape factors of soot particles were 1.7 to 2.5 and increasing with mass of aggregates. In the regime 0.2 < Kn < 0.7 (Knudsen number, Kn = 2/dmob) the mobility diameter dmob was observed to be proportional to the radius of gyration with a ratio dmob/2Rg = 0.81 ± 0.07. Specific surface area of aggregates was determined to be 70 ± 10 m2g−1 based on SEM image analysis. These parameters can be used directly in modelling microphysical behaviour of freshly formed soot particles from biomass combustion with fractal dimension of Df ≈ 1.80. Chemical composition and size distributions of particles were investigated on filter samples collected during intense winter brown haze episodes in Cape Town. The sampling technique offered the capability to characterise highly heterogeneous aerosols over a polluted urban environment. Based on morphology and elemental composition, particles were categorised into seven particle groups of: aggregated soot particles, mineral dust, sulphates (SO2− 4 ), sea-salt, tar balls/fly ash, rod-shaped particles associated with soot agglomerates and those that could not be attributed to any of these groups were labelled as ‘others’. Apportionments of chemical species were highly variable both spatially and temporally. These variations indicate lack of lateral mixing and dependence of particle chemical compositions on localised and point sources within the Cape Town area. Sulphate and aggregated soot particles were externally mixed with fractional number concentrations of 0− 82% and 11%−46%, respectively. Aerosol complex refractive indices were derived from the chemical apportionment and particle abundance determined in microscopy analyses. The refractive indices were combined with in-situ measurements of number-size distribution to determine optical properties of aerosols. Single scattering albedo, !0, varied from 0.61 to 0.94 with a mean value of 0.72±0.08. The !0 is much lower than is generally reported in literature, and this was attributed to high concentrations of highly absorbing anthropogenic soot observed in SEM analysis. The mean extinction coefficient ep was 194 ± 195 Mm−1. ep and !0 clearly demonstrated and explained quantitatively the visibility reduction due to particles in the Cape Town atmosphere, reduction observed as the brown haze phenomenon. In all the three case studies, microscopy single particle analysis played a critical role in advancing knowledge of understanding properties of aerosol particles in the atmosphere.