Exploring factors associated with health disparities in asthma and poorly controlled asthma among school-aged children in the U.S.

Objective: Certain populations suffer disproportionately from asthma and asthma morbidity. The objective was to provide a national descriptive profile of asthma control and treatment patterns among school-aged children (SAC: aged 6-17) in the U.S. Methods: This was a cross-sectional analysis using the nationally representative 2007-2014 Medical Expenditure Panel Survey. Among SAC with asthma, indicators of poor control included: exacerbation/asthma attack; >3 canisters short-acting beta agonist (SABA)/3 months; and asthma-specific Emergency Department or inpatient visits (ED/IP). Results: Non-Hispanic black, non-Hispanic multiple races, Puerto Rican, obese, Medicaid, poor, ≥2 non-asthma chronic comorbidities (CC), and family average CC ≥ 2 were associated with higher odds of having asthma. The following had significantly higher odds ratios (OR) of excessive SABA use compared to non-Hispanic whites [OR; CI; p < 0.05]: Puerto Rican (3.8; 2.1-6.9), Mexican (3.6; 2.0-6.4), Central/South American (3.0; 1.2-7.7), Hispanic-other (3.1; 1.1-9.0), non-Hispanic black (2.5; 1.6-3.9), and non-Hispanic Asian (4.0; 1.7-9.2). SABA OR were also significant for Spanish spoken at home (2.5; 1.6-3.8), obese (2.1; 1.3-3.3), Medicaid (2.9; 2.0-4.1), no medical insurance (2.1; 1.1-4.1), no prescription insurance (2.5; 1.8-3.5), poor (2.8; 1.7-4.7), CC ≥ 2 (2.1; 1.6-2.8), parent-without high-school degree (2.5; 1.8-3.6), parent-SF-12 Physical Component Scale <50 (1.6; 1.2-2.1) and Mental Component Scale <50 (1.5; 1.1-2.0). Significant differences also existed across subgroups for ED/IP visits. Conclusions: There are disparities in asthma control and prevalence among certain populations in the U.S. These results provide national data on disparities in several indicators of poor asthma control beyond the standard race/ethnicity groupings.

The national burden of poorly controlled asthma, school absence and parental work loss among school-aged children in the United States.

OBJECTIVE: The degree of poorly controlled asthma and its association with missed school days and parental missed work days is not well understood. METHODS: This was a retrospective analysis of missed school days and missed work days for school-aged children (SAC; aged 6-17) and their caregivers in the nationally representative 2007-2013 Medical Expenditure Panel Survey (MEPS). Indicators of poor asthma control included: exacerbation in previous 12 months; use of >3 canisters of short-acting beta agonist (SABA) in 3 months; and annual asthma-specific (AS) Emergency Department (ED) or inpatient (IP) visits. Negative binomial regression was used for missed school days, and a Heckman two-step selection model was used for missed work days. All analyses controlled for sociodemographics and other covariates. RESULTS: There were 44,320 SAC in MEPS, of whom 5,890 had asthma. SAC with asthma and an indicator of poor control missed more school days than SAC without asthma: exacerbation (1.8 times more; p < 0.001); >3 canisters SABA (2.7 times more; p < 0.001) and ED/IP visit (3.8 times more; p < 0.001). The parents/caregivers of SAC with asthma and an exacerbation missed 1.2 times more work days (p < 0.05), while those with SAC with asthma and an ED/IP visit missed 1.8 times more work days (p < 0.01) than the parents of SAC without asthma. CONCLUSIONS: This study provides evidence of the significant national burden of poorly controlled asthma due to missed school and work days in the United States. More effective and creative asthma management strategies, with collaboration across clinical, community and school-based outreach, may help address this burden.

Kinetics of tumor growth and regression in IgG multiple myeloma.

Studies of immunoglobulin synthesis, total body tumor cell number, and tumor kinetics were carried out in a series of patients with IgG multiple myeloma. The changes in tumor size associated with tumor growth or with regression were underestimated when the concentration of serum M-component was used as the sole index of tumor mass. Calculation of the total body M-component synthetic rate (corrected for concentration-dependent changes in IgG metabolism) and tumor cell number gave a more accurate and predictable estimate of changes in tumor size. Tumor growth and drug-induced tumor regression were found to follow Gompertzian kinetics, with progressive retardation of the rate of change of tumor size in both of these circumstances. This retardation effect, describable with a constant alpha, may be caused by a shift in the proportion of tumor cells in the proliferative cycle. Drug sensitivity of the tumor could be described quantitatively with a calculation of B(O), the tumor's initial sensitivity to a given drug regimen. Of particular clinical significance, the magnitude of a given patient's tumor regression could be predicted from the ratio of B(O) to alpha. Mathematical proof was obtained that the retardation constant determined during tumor regression also applied to the earlier period of tumor growth, and this constant was used to reconstruct the preclinical history of disease. In the average patient, fewer than 5 yr elapse from the initial tumor cell doubling to its clinical presentation with from 10(11) to more than 10(12) myeloma cells in the body. The reduction in total body tumor mass in most patients responding to therapy ranges from less than one to almost two orders of magnitude. Application of predictive kinetic analysis to the design of sequential drug regimens may lead to further improvement in the treatment of multiple myeloma and other tumors with similar growth characteristics.