Health resource utilisation associated with skeletal-related events in patients with bone metastases secondary to solid tumours: regional comparisons in an observational study.

Skeletal-related events (SREs) including spinal cord compression, pathologic fracture, and radiation or surgery to bone, occur frequently due to bone metastases in advanced cancer. This analysis of a multicentre, observational study was designed to describe cross-regional differences in health resource utilisation (HRU) of SREs in Western Europe and the US. Patients with bone metastases due to breast, lung or prostate cancer, or multiple myeloma who had experienced a SRE within the past 97 days were enrolled. Investigators recorded HRU associated with SREs, including hospitalisation and length of stay (LOS), outpatient visits, procedures and bisphosphonate use. This subanalysis includes 668 patients with solid tumours (US, n = 190 with 354 SREs; EU, n = 478 with 893 SREs). The rate of SREs associated with hospitalisation(s) was higher in the EU vs. the US (30% vs. 15%, P < 0.001) and LOS was longer in the EU [mean (SD) days/SRE: 19.87 (17.31) vs. 10.61 (9.39)]. However, the US was associated with higher rate of SREs with outpatient visits than the EU (88% vs. 74%, P < 0.0001) and more procedures [mean (SD)/SRE: 11.26 (7.94) vs. 6.91 (6.48)]. Bisphosphonates were less often used in the EU (65% vs. 76% of US, P = 0.0033). In patients experiencing SREs due to bone metastases, HRU patterns reflect regional diversity with a substantial burden in both regions.

Health resource utilization associated with skeletal-related events in patients with bone metastases: Results from a multinational retrospective - prospective observational study - a cohort from 4 European countries.

BACKGROUND: Skeletal-related events (SREs; pathologic fracture, radiation or surgery to bone, spinal cord compression) frequently occur in patients with advanced cancer with bone metastases/lesions. Limited data on the associated patient and economic burden are available to aid in resource planning and evaluating treatment options. METHODS: Patients with bone metastases/lesions secondary to breast, lung or prostate cancer or multiple myeloma; with at least one SRE within 97 days prior to enrollment; life expectancy of at least 6 months; and Eastern Cooperative Oncology Group performance status 0, 1 or 2 were recruited. Information on health resource utilization (HRU; including number/duration of hospitalizations, outpatient visits, procedures), attributed by investigators to be associated with a SRE, was collected retrospectively for up to 97 days prior to enrollment and prospectively for up to 18-21 months. RESULTS: A total of 631 patients contributing 1282 SREs, were enrolled across Germany, Italy, Spain and the United Kingdom. Approximately a third of all SREs required an inpatient stay. Mean duration of inpatient stay for patients with SREs requiring one ranged from 8.4 to 41.1 days across all countries and SRE types. CONCLUSION: All types of SREs are associated with substantial HRU burden. Preventing SREs by using the best therapeutic options available may help to reduce the burden to patients and healthcare systems.

Cost of skeletal-related events in European patients with solid tumours and bone metastases: data from a prospective multinational observational study.

OBJECTIVES: Patients with bone metastases often experience skeletal-related events (SREs: radiation or surgery to bone, pathologic fracture, and spinal cord compression). This study examined health resource utilization and costs associated with SREs. METHODS: Data presented are from the European cohort (Germany, Italy, Spain, and the UK) of patients with solid tumours enrolled in a multi-national, prospective, observational study in patients with solid tumours or multiple myeloma. Patients with Eastern Cooperative Oncology Group score 0-2 and life expectancy ≥6 months, who experienced an SRE up to 97 days before enrolment, were eligible. Health resource utilization associated with SREs (including number/length of inpatient stays, numbers of procedures and outpatient visits) were collected through chart review for up to 97 days before enrolment and prospectively during follow-up. Country-specific cost calculations were performed. RESULTS: In total, 478 eligible patients contributed 893 SREs to this analysis. Radiation to bone occurred most frequently (66% of total). Spinal cord compression (7%) and surgery to bone (10%) were the least common events, but most likely to require inpatient stays. The most costly SREs were also spinal cord compression (mean per SRE across countries, €4884-€12,082) and surgery to bone (€3348-€9407). Inpatient stays were the main cost drivers. LIMITATIONS: Health resource utilization used to calculate the costs associated with SREs may have been under-estimated as a result of exclusion of patients with low performance status or life expectancy; unavailable information and exclusion of resource consumption associated with pain. Thus, the estimate of associated costs is likely to be conservative. CONCLUSIONS: SREs result in considerable health resource utilization, imposing a substantial financial burden driven by inpatient stays. Treatments that prevent/delay SREs may help ease this burden, thereby providing cost savings across European healthcare systems.

A synthetic functional metabolic compartment. The role of propinquity in a linked pair of immobilized enzymes.

A system was created to model the influence of microcompartments on linked enzymatic reactions. Creatine kinase and hexokinase were covalently attached to Sepharose beads. The gel could be perfused in a specially constructed chamber inside a 360-MHz NMR spectrometer at different flow rates with solutions containing various concentrations of substrates. 31P NMR studies were carried out on the linked enzymatic reaction, creatine phosphate + glucose----creatine + glucose 6-phosphate in two enzyme gels differing in only one aspect, the average distance between hexokinase and creatine kinase. At a distance on the order of 0.1 mm between the enzymes, the average bulk concentrations of substrates and products in the perfusate determined the overall function of the linked system. At an average distance of the order of 10 nm, flux through the linked pair was much higher and much less dependent on the concentration of the intermediate substrate/product ADP/ATP. Even at adenine nucleotide concentrations far below the Km of hexokinase, substantial amounts of glucose 6-phosphate were produced when the enzymes were near but not when they were distant. From saturation transfer measurements and turnover calculations, the lifetime of ATP in the system is estimated to be 0.14-0.5 s when the enzymes are near. This compares to 6 s for distant enzymes. From this it appears that the pair of linked enzymes comprise a functional compartment supported by propinquity in which hexokinase has preferential access to ATP produced by creatine kinase, and creatine kinase to ADP from the hexokinase reaction.

Complete inhibition of creatine kinase in isolated perfused rat hearts.

Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure.

Observation of intracellular potassium and sodium in the heart by NMR: a major fraction of potassium is "invisible".

Using 39K and 23Na NMR in conjunction with extracellularly localized shift reagents, we have determined the intracellular concentrations of NMR visible sodium and potassium in isolated, perfused rat hearts. We find this concentration to be 9.9 mM/kg cell water for sodium and 31 mM/kg cell water for potassium. Values of activity determined by ion-sensitive microelectrodes are in good agreement with our sodium value but do not agree with our potassium value. Our results mean that a major pool of intracellular potassium is, on average, significantly immobilized and that the mobile NMR visible fraction (31 mM/kg) is not in exchange with the NMR invisible pool (114 mM/kg). The immobilized fraction is characterized by T2 values which are too short to be observed by our conventional spectrometer. This fraction is, therefore, said to be "invisible" under our experimental conditions.