Cost effectiveness of external hip protectors in the hospital setting: a modeling study.

Chronic illnesses, for which many patients are admitted to hospitals, substantially increase the risk of falling, and hence the likelihood of incurring a hip fracture. Hip fractures not only have devastating consequences on an individual's quality of life but may also affect a hospital's reputation in the community. In addition, hospitals may face litigation claims and increased costs for patients who fall and suffer a major injury as a consequence. External hip protectors are comparable to padded undergarments and shield the trochanter, reducing the detrimental effects and force impacting the bone during a fall. Screening for patients at high risk of falling and providing high-risk patients with hip protectors as a preventive measure to avoid hip fractures, not only improves public health, but can also save hospitals care and litigation costs.

Impact of diabetes on costs before and after major lower extremity amputations in Germany.

AIMS: To compare direct medical costs 1 year before up to 3 years after first major lower extremity amputation (LEA) between patients with and without diabetes. METHODS: We used health insurance claims data and included patients with a first major LEA between 2005 and 2009. Costs for hospitalization, rehabilitation, outpatient care, outpatient drug prescriptions, non-physician services, durable medical equipment and long-term care were assessed. We estimated cost ratios (CR) for diabetes status using generalized linear models adjusted for age, sex, amputation level, care dependency as well as observation time and mortality within the corresponding period and costs before LEA. RESULTS: We included 444 patients with first major LEA (58.3% had diabetes), 71.8% were male and the average age was 69.1 years. Total mean costs for 1 year before LEA were higher in patients with diabetes (24,504 vs. 18,961 Euros), which was also confirmed by the multivariate analysis (CR: 1.27; 95% CI: 1.06-1.52). Costs up to 24 weeks after LEA were virtually the same in both groups (36,686 vs. 35,858 Euros), but thereafter differences increase again with higher costs for diabetics. Costs for 3 years after LEA were 115,676 vs. 92,862 Euros, respectively (CR: 1.26; 95% CI: 1.12-1.42). Hospitalizations accounted for more than 50% of total costs irrespective of diabetes status and period. CONCLUSIONS: Costs up to 24 weeks after first major LEA are mainly driven by the amputation itself irrespective of diabetes. Thereafter, costs for diabetic patients were higher again, which underlines the importance of studying long-term costs.

Age of onset in chronic diseases: new method and application to dementia in Germany.

BACKGROUND: Age of onset is an important outcome to characterize a population with a chronic disease. With respect to social, cognitive, and physical aspects for patients and families, dementia is especially burdensome. In Germany, like in many other countries, it is highly prevalent in the older population and imposes enormous efforts for caregivers and society. METHODS: We develop an incidence-prevalence-mortality model to derive the mean and variance of the age of onset in chronic diseases. Age- and sex-specific incidence and prevalence of dementia is taken from published values based on health insurance data from 2002. Data about the age distribution in Germany in 2002 comes from the Federal Statistical Office. RESULTS: Mean age of onset of a chronic disease depends on a) the age-specific incidence of the disease, b) the prevalence of the disease, and c) the age distribution of the population. The resulting age of onset of dementia in Germany in 2002 is 78.8 ± 8.1 years (mean ± standard deviation) for men and 81.9 ± 7.6 years for women. CONCLUSIONS: Although incidence and prevalence of dementia in men are not greater than in women, men contract dementia approximately three years earlier than women. The reason lies in the different age distributions of the male and the female population in Germany.

Identification of a multistate continuous-time nonhomogeneous Markov chain model for patients with decreased renal function.

OBJECTIVES: Markov chain models are frequently used to study the clinical course of chronic diseases. The aim of this article is to adopt statistical methods to describe the time dynamics of chronically ill patients when 2 kinds of data sets--fully and partially observable data are available. MODEL: We propose a 6-state continuous-time Markov chain model for the progression of chronic kidney disease (CKD), where little is known about the transitions between the disease stages. States 1 to 3 of the model correspond to stages III to V of chronic kidney disease in the Kidney Disease Outcomes Quality Initiative (KDOQI) CKD classification. States 4 and 5 relate to dialysis and transplantation (renal replacement therapy), respectively. Death is the (absorbing) state 6. METHODS AND DATA: The model can be investigated and identified using Kolmogorov's forward equations and the methods of survival analysis. Age dependency, covariates in the form of the Cox regression, and unobservable risks of transition (frailties) can be included in the model. We applied our model to a data set consisting of all 2097 patients from all renal centers in a region in North Rhine-Westphalia (Germany) in 2005-2010. RESULTS: We compared transitions and relative risks to the few data published and found them to be reasonable. For example, patients with diabetes had a significantly higher risk for disease progression compared with patients without diabetes. CONCLUSIONS: In summary, modeling may help to quantify disease progression and its predictors when only partially observable prospective data are available.