21 research outputs found

    Varicose Veins : Aspects on Diagnosis and Surgical Treatment

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    Treatment for varicose veins (VV) is insufficiently evidence based and recurrence rates are high. The aim of this thesis was to study the long-term results after VV surgery, risk factors for recurrences and the effect of preoperative duplex scanning on recurrence rate, quality of life (QoL) and costs. In a follow-up study 89 patients with 100 legs operated on for VV 6–10 years earlier were re-examined with duplex, in 13 cases also with varicography. 57% had incompetent vessels in the groin visible with duplex, equally well defined by varicography. Residual branches could not be differentiated from new vessel formation. The recurrence rate did not correlate to the surgeon’s level of experience or perioperative difficulties at primary surgery. In a prospective randomized study 293 patients (343 legs) were operated on for primary VV with or without preoperative duplex. Duplex was done postoperatively, at 2 months and 2 years. QoL was measured with SF-36 preoperatively, at 1 month, 1 year and 2 years. After 2 years the number of reoperations were 2 in the group with preoperative duplex and 14 in the group without (p=0.002). Incompetent veins were seen in the saphenofemoral or saphenopopliteal junction in 19 and 53 legs respectively (p<0.001). Preoperative QoL was worse in the VV patients compared to a reference population, and was normalised 2 years postoperatively. The improved surgical result in the duplex group was not reflected in a significantly higher QoL. The lower costs for redo surgery in the duplex group did not offset the costs for duplex, partly due to more extensive primary surgery. A significant proportion of recurrences after 2 years was new vessel formation and progression of disease. Preoperative perforating vein incompetence did not influence recurrence rate, and was abolished without specific interruption in 60% at 2 years postoperatively

    Evaluation of an information system in an information seeking process : a holistic approach

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    The research objective of this thesis was to conduct a holistic evaluation of an operational information system. By holistic evaluation we mean that an equal focus was placed on both the system system perspective and its users user perspective, in the actual environment where the system and its users function contextuality. In addition, the methodological objective of the study was to test a new research approach in a real life setting. The participants of the study were twenty newspaper journalists employed at Göteborgs-Posten GP. The information system NewsLink is a manually indexed full-text database containing all articles published in GP since 1994. It employs Boolean search logic and offers a choice between showing the retrieved result ranked either by date or order of relevance. Our evaluation methodology consists of triangulation pre-search questionnaires; search log; post-interviewing and novel interactive performance measures the Ranked Half-Life measure, as well as Satisfaction and Novelty perception by users, supplementing Precision. It involves traditional algorithmic performance measures, usefulness situational relevance, and non-binary relevance judgements in an operational ranked IR system seen in the context of 1 work task fulfilment, and 2 other information resources. Our findings show that the system worked well for its users, but would gain considerably from the improvement of its interface. In sum, we found the method employed to be well suited for evaluating information systems in a real life setting as it ensures both realism and control.Uppsatsnivå:

    Venös insufficiens och tromboembolism

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