Using Patient Demographics and Statistical Modeling to Predict Knee Tibia Component Sizing in Total Knee Arthroplasty.

BACKGROUND: Preoperative planning is important to achieve successful implantation in primary total knee arthroplasty (TKA). However, traditional TKA templating techniques are not accurate enough to predict the component size to a very close range. METHODS: With the goal of developing a general predictive statistical model using patient demographic information, ordinal logistic regression was applied to build a proportional odds model to predict the tibia component size. The study retrospectively collected the data of 1992 primary Persona Knee System TKA procedures. Of them, 199 procedures were randomly selected as testing data and the rest of the data were randomly partitioned between model training data and model evaluation data with a ratio of 7:3. Different models were trained and evaluated on the training and validation data sets after data exploration. RESULTS: The final model had patient gender, age, weight, and height as independent variables and predicted the tibia size within 1 size difference 96% of the time on the validation data, 94% of the time on the testing data, and 92% on a prospective cadaver data set. CONCLUSION: The study results indicated the statistical model built by ordinal logistic regression can increase the accuracy of tibia sizing information for Persona Knee preoperative templating. This research shows statistical modeling may be used with radiographs to dramatically enhance the templating accuracy, efficiency, and quality. In general, this methodology can be applied to other TKA products when the data are applicable.

The Treatment for Adolescents With Depression Study (TADS): outcomes over 1 year of naturalistic follow-up.

OBJECTIVE: The Treatment for Adolescents With Depression Study (TADS) evaluates the effectiveness of fluoxetine, cognitive-behavioral therapy (CBT), and their combination in adolescents with major depressive disorder. The authors report effectiveness outcomes across a 1-year naturalistic follow-up period. METHOD: The randomized, controlled trial was conducted in 13 academic and community sites in the United States. Stages I, II, and III consisted of 12, 6, and 18 weeks of acute, consolidation, and continuation treatment, respectively. Following discontinuation of TADS treatments at the end of stage III, stage IV consisted of 1 year of naturalistic follow-up. The participants were 327 subjects between the ages of 12 and 17 with a primary DSM-IV diagnosis of major depressive disorder. No TADS treatment was provided during the follow-up period; treatment was available in the community. The primary dependent measures, rated by an independent evaluator blind to treatment status, were the total score on the Children's Depression Rating Scale-Revised and the rate of response, defined as a rating of much or very much improved on the Clinical Global Impressions improvement measure. RESULTS: Sixty-six percent of the eligible subjects participated in at least one stage IV assessment. The benefits seen at the end of active treatment (week 36) persisted during follow-up on all measures of depression and suicidality. CONCLUSIONS: In contrast to earlier reports on short-term treatments, in which worsening after treatment is the rule, the longer treatment in the TADS was associated with persistent benefits over 1 year of naturalistic follow-up.

Gender, kinship and caregiver burden: the case of community-dwelling memory impaired seniors.

BACKGROUND: This study examined whether there were gender and kinship (spouse, child, more distant relative) differences in caregiver burden. It further examined the constellation of gender and kinship by examining whether adult daughter caregivers experienced greater burden compared to wives, husbands, sons, and other more distant relatives. METHODS: The sample consisted of 305 family caregivers of memory-impaired individuals who were age 70 years or older and resided in non-institutional settings in Arkansas. A cross-sectional design was employed using validated measures to assess both the memory-impaired elders' and family caregivers' self-reported physical and memory status. RESULTS: After controlling for the age and health status characteristics of the memory-impaired elder, sociodemographic and health status characteristics of the family caregiver, and the caregiver coping response (measured by the sense of coherence), multiple regression analyses found kinship, but not gender differences in caregiver burden. Adult children experienced more caregiver burden than more distant relatives. There were no significant differences in caregiver burden between adult children and spouses. Adult daughters had greater caregiver burden scores compared to more distant relatives, but had comparable scores to wives, sons, and husbands. Other significant correlates of burden included caregiver personal characteristics (age and ethnicity) and the sense of coherence. CONCLUSIONS: The study discusses the practice implications of adult children and adult daughters' propensity to suffer burden when caring for their memory-impaired parents living in the community. It also discusses the relevance of caregiver personal characteristics and the sense of coherence as correlates of burden.