Using 12-month post treatment Timeline Followback drinking reports, data extrapolated from shorter time windows (e.g., 1 month, 6 months) were used to estimate total annual drinking. The objective was to determine whether data from a shorter time window would provide an estimate of annual drinking sufficiently consistent with the full year report such that it can be used in place of the full report. Data for this study were obtained from problem drinkers who voluntarily participated in a randomized controlled trial of a mail-based intervention. Complete follow-up data were obtained for 467 of the 825 participants who completed a 12-month Timeline Followback of their post intervention drinking. The results of this study suggest that 3 months is the necessary minimum time window to best represent annual posttreatment drinking with alcohol abusers. The major implication of this finding is that alcohol treatment outcome studies can use a shorter posttreatment time window, which is more time and resource efficient, over which to obtain follow-up data with little to no loss in the representativeness of that data.

<p>This thesis investigates health trends among very old people and the allocation of public home-help services. A further aim is to examine methodological issues in mortality analysis. Three data sources are used: (1) The Tierp study of community-dwelling persons (n=421, ages 75+), (2) the SWEOLD nationally representative samples (n=537 in 1992 and n=561 in 2002, ages 77+), and 3) SNAC-K comprised of home-help recipients in a district of Stockholm (n=1108, ages 65+).</p><p>Study I suggests that the length of the follow-up period may explain some of the differences found in predictor strength when comparing mortality studies. Predictors that can change rapidly (e.g., health) were found to be strongest for the short term, with a lower average mortality risk for longer follow-ups. Stable variables (e.g., gender) were less affected by length of follow-up.</p><p>Studies II and III present a measure of complex health problems based on serious problems in at least two of three health domains. These were diseases/symptoms, mobility, and cognition/communication. Prevalence of complex health problems increased significantly between 1992 and 2002. Older age, female gender, and lower education increased the odds of having complex problems. Complex problems strongly predicted 4-year mortality. Controlled for age, gender, health, and education, mortality decreased by 20% between 1992 and 2002. Men with complex problems accounted for this decrease. Thus, in 2002 the gender difference in mortality risk was almost eliminated among the most vulnerable adults.</p><p>Study IV revealed that physical and cognitive limitations, higher age, and living alone were significantly related to home-help allocation, with physical and cognitive limitations dominating. Psychiatric symptoms did not affect the assessment.</p><p>The increased prevalence of complex health problems and increased survival among people with complex needs have important implications concerning the need for collaboration among service providers.</p>

This thesis investigates health trends among very old people and the allocation of public home-help services. A further aim is to examine methodological issues in mortality analysis. Three data sources are used: (1) The Tierp study of community-dwelling persons (n=421, ages 75+), (2) the SWEOLD nationally representative samples (n=537 in 1992 and n=561 in 2002, ages 77+), and 3) SNAC-K comprised of home-help recipients in a district of Stockholm (n=1108, ages 65+). Study I suggests that the length of the follow-up period may explain some of the differences found in predictor strength when comparing mortality studies. Predictors that can change rapidly (e.g., health) were found to be strongest for the short term, with a lower average mortality risk for longer follow-ups. Stable variables (e.g., gender) were less affected by length of follow-up. Studies II and III present a measure of complex health problems based on serious problems in at least two of three health domains. These were diseases/symptoms, mobility, and cognition/communication. Prevalence of complex health problems increased significantly between 1992 and 2002. Older age, female gender, and lower education increased the odds of having complex problems. Complex problems strongly predicted 4-year mortality. Controlled for age, gender, health, and education, mortality decreased by 20% between 1992 and 2002. Men with complex problems accounted for this decrease. Thus, in 2002 the gender difference in mortality risk was almost eliminated among the most vulnerable adults. Study IV revealed that physical and cognitive limitations, higher age, and living alone were significantly related to home-help allocation, with physical and cognitive limitations dominating. Psychiatric symptoms did not affect the assessment. The increased prevalence of complex health problems and increased survival among people with complex needs have important implications concerning the need for collaboration among service providers.

In Florida, the increased installation of non-traversable medians and directional median opening has produced an increased number of U-turns on multilane highways. Arguments have been advanced by some opponents of median modification projects that the increased numbers of U-turns may result in safety and operational problems on multilane highways. The primary objective of this study is to evaluate the operational effects of U-turn movement on multilane roadways. To achieve this research objective, extensive data were collected. Field measurements were conducted at 40 sites in the Tampa Bay area of Florida to collect traffic operations data. Besides, the crash histories of 179 selected roadway segments in central Florida were investigated. Statistical analysis was conducted based on the collected traffic operations data and crash data to quantitatively evaluate the operational performance of U-turn movement. Delay and travel time were compared for different driveway left- turn alternatives that are widely used in Florida and nationally. Crash rate models were developed to evaluate how the separation distance between a driveway exit and the downstream U-turn bay impacts the safety performance of vehicles making right-turns followed by U-turns (RTUT). With the crash data analysis results, the minimum separation distances under different roadway conditions were determined to facilitate driver use of RTUTs. The capacity of U-turn movement was analyzed under two different situations: (1) U-turns are provided at a signalized intersection; and (2) U-turns are provided at an unsignalized intersection. Adjustment factors were developed to quantify the impacts of the presence of U-turning vehicles on the capacity of a signalized intersection. The critical gaps and follow-up time for U-turn movement at unsignalized intersections were estimated. With the estimated critical gaps and follow-up time, the Harders model was used to determine the capacity of U-turn movem ent at an unsignalized intersection. This study also looks extensively at the minimum roadway width and median width required by vehicles to perform U-turn maneuvers on 4-lane divided roadways. It was found that a roadway width of 46 ft is generally sufficient for most types of design vehicles (except heavy vehicles) to perform a continuous U-turn maneuver without impedance.

The objective of the study was to identify the factors that affect the survival lifetime of HIV+ terminal patients in rural district hospitals of Albert Luthuli municipality in the Mpumalanga province of South Africa. A cohort of HIV+ terminal patients was retrospectively followed from 2010 to 2017 until a patient died, was lost to follow-up or was still alive at the end of the observation period. Nonparametric survival analysis and semiparametric survival analysis methods were used to analyse the data. Through Cox proportional hazards regression modelling, it was found that ART adherence (poor, fair, good), Age, Follow-up mass, Baseline sodium, Baseline viral load, Follow CD4 count by Treatment (Regimen 1) interaction and Follow-up lymphocyte by TB history (yes, no) interaction had significant effects on survival lifetime of HIV+ terminal patients (p-values<0.1). Furthermore, through quantile regression modelling, it was found that short, medium and long survival times of HIV+ patients, respectively represented by the 0.1, 0.5 and 0.9 quantiles, were not necessarily significantly affected by the same factors. / Statistics / M. Sc. (Statistics)