The Significance of Selected Medical and Environmental Factors in The Etiology of Falling Incidents Among The Hospitalized Elderly: A Relative Risk Assessment

99 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981.The leading cause of traumatic disability and death by injury in the elderly population is falls. While the elderly most often fall at home, the falls which occur in the hospital are more amenable to scientific investigation. Within the hospital setting, detailed records of circumstances surrounding falls permit various approaches to the investigation and understanding of how falls occur. However, a study of falls among the hospitalized elderly can only be generalized to a fraction of the elderly population who become acutely ill and require hospitalization.The purpose of this study was to investigate the relative importance of medical and environmental risk factors for falling among the hospitalized elderly. In one geriatric facility, the degree of risk of falling was assessed for patients who had one or more significant medical risk factors. In addition, the degree of risk associated with specific hospital environments, and patient activities within those environments, were also assessed.Data were collected in three phases: a falling incident analysis, a case-control study, and an exposure study. Data were gathered retrospectively in Phases One and Two from incident reports and medical records. Phase Three data were gathered by direct observation of patient activities in the hospital.A total of 291 falling incidents were analyzed during Phase One. Descriptive data from this analysis provided information which identified individual patients by number. The incident reports also identified activity prior to fall, which was used in conducting Phase Three.Phase Two was a case-control study of 173 patients who fell and a randomly selected group of 339 patients who did not have a reported fall. Fallers were group-matched by length of stay in the hospital to non-fallers. Eighteen variables were examined in this phase: nine related to medication, five related to medical condition, three demograhic variables, and prior history of falling before entering the hospital. These variables were then used to determine the "best" multiple regression model to predict patients as fallers or non-fallers. The statistical analysis calculated the influence of each variable on falling while controlling for the effects of the remaining variables.Phase Three was a study of random observations of patient activities made over seven days, during the day and night-time hours. A relative risk assessment scale of geriatric patient activities was the outcome of this phase.The results indicated that patients getting out of bed or wheelchair to walk to the bathroom were at high risk of falling. The act of sitting down on the toilet was also a high risk activity. The presence of bedside rails in the up position, urine on the floor near where the fall occurred, and physical restraints were the most often cited contributing factors. The case-control study showed that patients on psychoactive medication were 3.4 times as likely to fall as patients not on such medication; patients with urinary dysfunction were 1.8 times as likely to fall as patients without urinary dysfunction; and male patients were 1.8 times as likely to fall as female patients. The regression model was validated, in part, by an examination of a subsequent sample of patient falls in 1980. Approximately 90 percent of all patients on psychoactive medications were moved to a new psychiatric unit which opened in January, 1980. During September and October 1980, the falling rate per 1,000 patient-days for this unit was 3.1 times higher than the rate for the remainder of the facility.These findings suggest that some patients have a greater tendency to fall, and that some patient activities present a greater risk than others. Results of this study need to be replicated in other geriatric facilities.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Analysis of recurrent event data under the case-crossover design with applications to elderly falls

SUMMARY The case-crossover design is useful for studying the effects of transient exposures on short-term risk of diseases or injuries when only data on cases are available. The crossover nature of this design allows each subject to serve as his own control. While the original design was proposed for univariate event data, in many applications recurrent events are often encountered (e.g., elderly falls, gout attacks, and sexually transmitted infections). In such situations, the within-subject dependence among recurrent events needs to be taken into account in the analysis. We review three existing conditional logistic regression-based approaches for analyzing recurrent event data under the case-crossover design. A simple approach is to use only one (e.g. the first) event for each subject, such that no assumption on the correlation among multiple events is needed, while we would expect loss of efficiency in estimation. events, conditionally on a subject-level latent variable and a set of observed time-varying covariates. In this paper, we propose to adjust the conditional logistic regression using either a within-subject pairwise resampling technique or a weighted estimating equation. No specific dependency structure among the recurrent events is needed for these two methods. We also propose a weighted MantelHaenszel estimator for situations with a binary exposure. Simulation studies are conducted to evaluate the performance of the discussed methods. We present the analysis of a study of the effect of medication changes on falls among the elderly

A case-crossover study of laceration injuries in pork processing

Objectives— The authors estimated the associations between transient risk factors and laceration injuries in workers at two meatpacking plants in the Midwest. Methods— The case-crossover design was used to collect within-subject transient work task and personal-level exposure information. RRs of laceration injuries were estimated by comparing exposures during the ‘hazard’ period (just before the laceration injury) with exposures in the ‘control’ period (the previous workweek). Stratified analyses were utilized to estimate the effects of gender, ethnicity, training and the number of adjacent coworkers on each transient risk factor. Results— The authors interviewed 295 meatpacking workers with laceration injuries (mean age 36.6 years, SD 11.2, 75% men, 48% Hispanic). Recent tool sharpening (RR 5.3, 95% CI 3.8 to 7.4) and equipment malfunction (RR 5.3, 95% CI 3.9 to 7.3) were associated with the highest RR for laceration injury, followed by using an unusual work method to accomplish a task (RR 4.1, 95% CI 2.6 to 6.4) and performing an unusual task (RR 2.3, 95% CI 1.8 to 3.0). Rushing and being distracted were not significantly associated with an elevated RR of a laceration injury. In stratified analyses, there were a number of significant differences in laceration risk factors by gender, ethnicity, training, and number of workers on the line. Conclusions— Sharpening tools, equipment malfunction, using an unusual work method to accomplish a task and performing an unusual task were all associated with increased risk of lacerations. Expanded training in atypical work circumstances and evaluation of tool sharpening procedures are intervention areas in meatpacking that need examination