How can we improve targeting of frail elderly patients to a geriatric day-hospital rehabilitation program?

BACKGROUND: The optimal patient selection of frail elderly persons undergoing rehabilitation in Geriatric Day Hospital (GDH) programs remains uncertain. This study was done to identify potential predictors of rehabilitation outcomes for these patients. METHODS: This study is a retrospective cohort analysis of patients admitted to the rehabilitation program of our GDH, in Montreal, Canada, over a five year period. The measures considered were: Barthel Index, Older Americans Resources and Services, Folstein Mini Mental Status Exam, Timed Up & Go (TUG), 6-minute walk test (6 MWT), Gait speed, Berg Balance, grip strength and the European Quality of life - 5 Dimensions. Successful improvement with rehabilitation was defined as improvement in three or more tests of physical function. Logistic regression analysis using the Bayesian Information Criterion (BIC) was employed to select the optimal model for making predictions of rehabilitation success. RESULTS: A total of 335 patients were studied, but only 233 patients had a complete data set suitable for the predictive model. Average age was 81 years and patients attended the GDH an average of 24 visits. Significant changes were found in several measures of physical performance for many patients ranging from improved gait speed in 21.3% to improved TUG in 62.7% of the cohort. Fifty-eight percent of patients attained successful improvement with rehabilitation by our criteria. This group was characterized by lower test scores on admission. Using BIC, the best predictor model was the 6 MWT [OR: 0.994 per meter walked (95% CI: 0.990-0.997)]. CONCLUSIONS: The GDH rehabilitation program is effective in improving patients' physical performance. Although no single measure was found to be sufficiently predictive to help target candidates appropriately, the 6 MWT showed a trend to significance. Further research will be done to elucidate the utility of a composite 'rehab appropriateness index' and the role of International Classification of Function concepts for targeting frail elderly to GDH rehabilitation services.

The impact of prefracture and hip fracture characteristics on mortality in older persons in Brazil.

BACKGROUND: Hip fractures in the elderly are common and associated with considerable mortality and disability. Although well known in industrialized countries, the factors associated with mortality after hip fractures are not reported frequently in developing countries and little is known regarding risk factors in Latin America. QUESTIONS/PURPOSE: We investigated the rate of 1-year mortality and prefracture and fracture characteristics associated with mortality after a hip fracture in elderly Brazilian patients in a large metropolitan area. METHODS: Two hundred forty-six persons 60 years and older admitted to four hospitals in Rio de Janeiro were included after experiencing fractures and were followed for 1 year. Data were collected on sociodemographic, health, and functional status; type of surgery; length of stay; and complications after surgery. Cox regression analyses were conducted to investigate factors associated with 1-year mortality after hip fracture. RESULTS: Of the 246 patients, 86 died (35%). Of those 86, 22 died in the hospital (25.6%) and 64 (74.4%) died after discharge. Functional status before fracture, older age, male gender, and higher surgical risk increased the risk of mortality, whereas the use of antibiotics and the use of physical therapy after surgery decreased the risk. CONCLUSIONS: Our mortality rate was higher than those reported from industrialized countries. The use of antibiotics and physical therapy are potentially modifiable factors to improve patients' survival after fracture in Brazil. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of the levels of evidence.

The impact of hip fracture (HF) on the functional status (FS) of older persons in Rio de Janeiro, Brazil: results of a prospective cohort study.

There is no prospective study investigating the impact of hip fracture (HF) on functional status (FS) in Brazil. The objective of this study was to investigate the impact of a HF on the FS of older persons 1 year after the fracture and the factors associated with decline in FS 1 year after the fracture. Two hundred and forty-six patients who were admitted to one of four hospitals after HF participated. The sample for this study consisted of 160 patients who were still alive and had information on functional limitations after 1 year. The Brazil Old Age Schedule (BOAS) was used to assess FS before and 1 year after HF. Logistic regression analyses were used to identify predictors of decline 1 year after fracture. Of the patients, 46.3% did not achieve their prior FS. Older age, being underweight, total length of stay and the use of psychotics/sedatives and anxiolitics were associated in multivariate analyses with decline in FS. Working before the fracture was protective of decline in FS. We conclude that HF severely compromised the FS of older persons in Rio de Janeiro, Brazil.

Active site titration as a tool for the evaluation of immobilization procedures of penicillin acylase.

Native and immobilized preparations of penicillin acylase from Escherichia coli and Alcaligenes faecalis were studied using an active site titration technique. Knowledge of the number of active sites allowed the calculation of the average turnover rate of the enzyme in the various preparations and allowed us to quantify the contribution of irreversible inactivation of the enzyme to the loss of catalytic activity during the immobilization procedure. In most cases a loss of active sites as well as a decrease of catalytic activity per active site (turnover rate) was observed upon immobilization. Immobilization techniques affected the enzymes differently. The effect of increased loading of penicillin acylase on the average turnover rate was determined by active site titration to assess diffusion limitations in the carrier.

Evaluation of the performance of immobilized penicillin G acylase using active-site titration.

Penicillin G acylase from Escherichia coli was immobilized on Eupergit C with different enzyme loading. The activity of the immobilized preparations was assayed in the hydrolysis of penicillin G and was found to be much lower than would be expected on the basis of the residual enzyme activity in the immobilization supernatant. Active-site titration demonstrated that the immobilized enzyme molecules on average had turnover rates much lower than that of the dissolved enzyme. This was attributed to diffusion limitations of substrate and product inhibition. Indeed, when the immobilized preparations were crushed, the activity increased from 587 U g-1 to up to 974 U g-1. The immobilized preparations exhibited up to 15% lower turnover rates than the dissolved enzyme in cephalexin synthesis from 7-ADCA and D-(-)-phenylglycine amide. The synthesis over hydrolysis ratios of the immobilized preparations were also much lower than that of the dissolved enzyme. This was partly due to diffusion limitations but also to an intrinsic property of the immobilized enzyme because the synthesis over hydrolysis ratio of the crushed preparations was much lower than that of the dissolved enzyme.