Private insurance versus medicaid and adherence to medication in older adults with fibromyalgia

Background: Fibromyalgia, defined as chronic, wide-spread musculoskeletal pain, affects 4 to 10 million Americans and up to 6% of the world population. Medication nonadherence results in $100 to$300 billion in US health expenditures annually. Previous studies have examined medication adherence in commercial health plans or public health plans, but relatively few have compared both populations. The purpose of this study was to estimate the effect of type of insurance on adherence to medication for older adults with fibromyalgia. Methods: The retrospective cohort study analyzed medical claims of fibromyalgia patients collected between January 1, 2005 to June 30, 2011 from the Blue Cross Blue Shield South Carolina State Health Plan (BCBS) and Medicaid data. Older adults age 60 and older were included if they were prescribed duloxetine, milnacipran, or pregabalin (N=3,187). The primary outcome, medication adherence, was defined as having a medication possession ratio (MPR) of ≥ 80%. Independent variables included health insurance, FMS medication, selected comorbidities (FMS-related, musculoskeletal pain, or neuropathic pain), gender, age, and the interaction between health insurance type and treatment. Results: Logistic regression showed older adults with fibromyalgia on Medicaid were over 3 times more likely to be adherent when compared to BCBS in both unadjusted (OR: 3.21, p<0.0001) and adjusted models (OR: 3.74, p<0.0001). Conclusion: Most states do not require a Medicaid prescription co-pay; whereas, private insurers, like Blue Cross Blue Shield, require more out-of-pocket costs. Our study suggests that the co-pays for medications in private plans may present a barrier to patient adherence

Novel Quenched Disorder Fixed Point in a Two-Temperature Lattice Gas

We investigate the effects of quenched randomness on the universal properties of a two-temperature lattice gas. The disorder modifies the dynamical transition rates of the system in an anisotropic fashion, giving rise to a new fixed point. We determine the associated scaling form of the structure factor, quoting critical exponents to two-loop order in an expansion around the upper critical dimension d$_c=7$. The close relationship with another quenched disorder fixed point, discovered recently in this model, is discussed.Comment: 11 pages, no figures, RevTe

Stability of a Nonequilibrium Interface in a Driven Phase Segregating System

We investigate the dynamics of a nonequilibrium interface between coexisting phases in a system described by a Cahn-Hilliard equation with an additional driving term. By means of a matched asymptotic expansion we derive equations for the interface motion. A linear stability analysis of these equations results in a condition for the stability of a flat interface. We find that the stability properties of a flat interface depend on the structure of the driving term in the original equation.Comment: 14 pages Latex, 1 postscript-figur

Review of the k-Body Embedded Ensembles of Gaussian Random Matrices

The embedded ensembles were introduced by Mon and French as physically more plausible stochastic models of many--body systems governed by one--and two--body interactions than provided by standard random--matrix theory. We review several approaches aimed at determining the spectral density, the spectral fluctuation properties, and the ergodic properties of these ensembles: moments methods, numerical simulations, the replica trick, the eigenvector decomposition of the matrix of second moments and supersymmetry, the binary correlation approximation, and the study of correlations between matrix elements.Comment: Final version. 29 pages, 4 ps figures, uses iopart.st