Patient characteristics and healthcare utilization patterns associated with unused medications among medicare patients.

OBJECTIVE: To examine what patient characteristics and healthcare utilization patterns are associated with the likelihood of having unused medications among elderly Medicare patients. DESIGN: Secondary data analysis combining insurance claims and phone survey data of Medicare Advantage members. SETTING: Regional health plan in Central Pennsylvania. PARTICIPANTS: 528 Medicare Advantage members (age 65 and older), who had Medicare Part D coverage through Geisinger Health Plan as of December 31, 2013, and completed the phone survey in May of 2014. MAIN OUTCOME: Member survey response indicating whether or not the member had any unused medication at the time of the survey. RESULTS: 27% of the patients in the sample (142 out of 528) indicated having one or more unused medications. In a bivariate analysis, these patients had higher prevalence of chronic conditions, utilized more medical care (more emergency department visits and physician office visits), and incurred higher cost of care. In a multivariate analysis, patients who received medications with days' supply greater than 30 (odds ratio (OR) = 1.59; p = 0.03) and utilized more acute care (defined as inpatient admissions or emergency department visits) (OR = 4.2; p = 0.04) were more likely to have unused medications. Moreover, patients who were advised by health care professionals about proper medication disposal were less likely to have unused medications (OR = 0.52; p = 0.04). CONCLUSION: These findings suggest potential ways to develop effective strategies to reduce amounts of unused medications. Such strategies are likely to involve limiting quantities of medications dispensed at each fill, and patient education on proper disposal of unused medications, particularly during care transitions.

Improving the imprinting effect by optimizing template:monomer:cross-linker ratios in a molecularly imprinted polymer for sulfadimethoxine.

Four non-covalently prepared molecularly imprinted polymers (MIPs) for sulfadimethoxine (SDM) were prepared using different ratios of SDM template, methacrylic acid monomer, and ethylene glycol dimethacrylate cross-linker. The imprinting factor (IF) was calculated by comparing the retention of SDM on the imprinted polymer with a comparable non-imprinted polymer. The template:monomer:cross-linker ratio of 1:6:20 resulted in an IF of 3.94 which is higher than found in previous studies. A significant decrease in IF to 0.89 when template:cross-linker ratio was 1:40 contradicts most literature where higher cross-linker concentration improves selectivity. IF was 4.36 when 20% water was added to the acetonitrile HPLC mobile phase during evaluation. Retention of SDM increased as water concentration changed as: 20, 40, 0, 60 and 70%, indicating a combination of shape recognition, hydrogen bonding and hydrophobic interactions contributing to retention of analyte. The MIP has the potential for use in SPE for purification and concentration of SDM and with further optimization, possibly direct HPLC analysis.

Development of a molecularly imprinted polymer for the analysis of avermectin.

Five molecularly imprinted polymers (MIPs) were synthesized for a large molecule, avermectin, using different preparation techniques, monomers, and polymerization solvents. Selectivities (α) of each were compared using HPLC and different mobile phases containing various levels of acetic acid. Selectivity (α) for avermectin was greatest (α estimated ≥18) when the polymer was prepared non-covalently (utilizing only non-covalent interactions between avermectin and monomer) in chloroform using methacrylic acid (MAA) monomer and evaluated in chloroform. When evaluated in acetonitrile, an MIP prepared in acetonitrile provided better selectivity (α=8.4) than the polymer prepared in chloroform. Optimizing mobile phase conditions by adding acetic acid was much more important when MIPs were evaluated in chloroform than in acetonitrile. MIPs prepared with MAA provided better selectivity than a polymer prepared with acrylamide monomer. Covalent preparation of two MIPs utilizing a covalent bond between avermectin and monomer before polymerization did not improve selectivity but did improve peak shape in chromatograms. Specificity was demonstrated by comparing the selectivity of avermectin with eprinomectin (α=3.0), a compound with a very similar structure. Results indicate that an MIP can be prepared for the large avermectin molecule, and has the potential to simplify sample preparation and to reduce the time needed for analysis.

Case study I: application of the divalent cation bridging theory to improve biofloc properties and industrial activated sludge system performance-direct addition of divalent cations.

The objectives of this study were to examine the application of the divalent cation bridging theory (DCBT) to improve settling, dewatering, and effluent quality in pilot-scale reactors and a full-scale system treating an industrial wastewater. This was accomplished by lowering the monovalent-to-divalent (M/D) cation ratio by direct divalent cation addition. Research has shown that the M/D ratio is a potential indicator for settling and dewatering problems at wastewater treatment plants, and M/D ratios above 2 have been associated with poor settling, dewatering, and effluent quality. The M/D ratio of the wastewater in this study ranged from 6 to 20. The cations studied were calcium and magnesium. Results showed that the addition of calcium improved floc properties compared to control reactors with no calcium addition. The reductions in sludge volume index, effluent chemical oxygen demand (COD), and effluent total suspended solids (TSS) were approximately 35, 34, and 55%, respectively, when the M/D ratio was decreased to approximately 2:1. In addition, the cake solids from a belt filter press simulator increased by 72% and the optimum polymer dose required for conditioning was reduced by 70% in the reactor fed the highest calcium concentration when compared to control reactors with no calcium addition. The addition of calcium also decreased the negative effect of high filamentous organism numbers. In general, the addition of magnesium (Mg2+) had similar effects on effluent quality and dewatering properties, although some differences were measured. A full-scale test using calcium addition was performed. Measurements of effluent quality and floc properties were performed before, during, and after the calcium (Ca2+) addition period. The average M/D ratio during these periods was 6.2, 4.6, and 14.0, respectively. The addition of Ca2+ decreased the effluent five-day biochemical oxygen demand, effluent TSS, and effluent COD. The increased Ca2+ concentration also improved dewatering measured by a decrease in specific resistance to filtration and capillary suction time. Overall, the addition of divalent cations to the pilot- and full-scale activated sludge systems improved floc properties and the data fit well with the DCBT.