Predictors of the prescribing of asthma pharmacotherapy in the ambulatory patient population of the United States

This study attempted to determine if select patient and physician demographic variables are predictors of the prescribing of asthma pharmacotherapy in the ambulatory patient population of the United States. Another aim of this study was to evaluate if physician prescribing behavior of asthma pharmacotherapy was in compliance with the recommendations of the National Heart, Lung & Blood Institute's National Asthma Education and Prevention Program Expert Panel 2 national asthma guidelines. An integrated framework that incorporated concepts from the medical-sociological model of physician behavior proposed by Eisenberg, the Diffusion of Innovation Model developed by Rogers, the Knowledge-Attitudes-Behavior Model of barriers to physician adherence to guidelines as proposed by Cabana and the modified Health Belief Model of patient adherence to pharmacotherapy as proposed by Balkrishnan, was developed and was used as the theoretical framework for this study.; This study was a retrospective cross-sectional study that used data from the National Ambulatory Medical Care Survey (NAMCS) from 1998 through 2004. The weighted population sample size of the study was 82,020,318 patients. There were 1540 observations in this study (pre-weighted sample size) and there were 96 strata, with 446 Population Sampling Units (PSUs). Specific patient demographic variables, physician demographic variables and asthma medications prescribed were extracted from the dataset and analyzed. Descriptive statistics for the patient demographic, physician demographic and asthma pharmacotherapy variables were generated. A series of logistic regression models were created with the choice of asthma pharmacotherapy agent used as the dependent variable and the patient and physician demographic variables as the independent variables.; The major finding from the study was that physicians did not seem to be adhering to the EPR-2 pharmacotherapy guidelines. This study found that there was no appreciable increase in the prescribing of inhaled corticosteroid inhaler (ICS) agents between the years 1998 through 2004. Additionally, the prescribing of short acting bronchodilator (SABA) agents continued to be unacceptably high during the same time period. Another major finding from this study was the fact that there were vulnerable sub-populations of asthma patients that were receiving sub-optimal asthma pharmacotherapy. Elderly patients (persons who were 65 years old or older) were less likely to be prescribed controller medications, long acting bronchodilator (LABA), combinations of ICS and LABA agents (LABIC) and SABA agents when compared to 35 to 64 year old patients. It was also found that patients who were non-white and non-African American were also less likely to receive optimal asthma pharmacotherapy. The majority of these patients were of Asian origin. These individuals were less likely to be prescribed controller medications, ICS agents, LABA agents and LABIC agents when compared to whites. Additionally, these individuals were more likely to be prescribed SABA agents when compared to whites. This study did not find a specific physician demographic variable that was strongly and consistently linked to physician prescribing behavior of asthma pharmacotherapy. However; patient status, physician specialty, ownership status and physician employment status were important variables in certain aspects of asthma pharmacotherapy.; In conclusion, it appears that a more concerted effort needs to be undertaken to improve physician adherence to the EPR-2 guidelines, especially in the prescribing of asthma pharmacotherapy. There is also a need to address the disparities observed in the prescribing of asthma pharmacotherapy in vulnerable, underserved populations.