Structural Characteristics Associated with Innovative Behavior of Pharmacies.

This dissertation addresses issues raised by the passage of state drug product selection laws. These laws allow ( and sometimes require) pharmacists to substitute less costly generically equivalent products when prescribers order multiple-source drug entities by their br and names. Information available to date suggests that the legislative intent has not been translated into widespread drug product selection (substitution). Though drug product selection rates (DPS rates) are quite low, variation has been noted among pharmacies. This research sought to identify pharmacy characteristics which influence the DPS rate. The framework for the study of this problem included issues raised by the innovation literature, issues of problem solving or situational constraints, and issues of professional or community relationships. A stratified r and om sample of noninstitutional pharmacies was selected for each state (130 Michigan pharmacies and 114 Wisconsin pharmacies) with the probability of selection proportional to new prescription volume. Secondary analysis of data from a four year evaluation of DPS legislation in Michigan and Wisconsin was undertaken to examine the relationships among pharmacy characteristics and DPS rates. The analysis consisted of descriptive measures, studies of marginal homogeneity, bivariate measures of association, and multivariate analysis. The effect of time was demonstrated in Wisconsin, however, "new adoption" (of DPS behavior in a pharmacy) was more often an explanation for the effect of time than "discontinuance." The expected negative effect of management/ownership on DPS rates was apparent only for Michigan pharmacies. Measures of external accountability were generally negatively associated with DPS rates in both states implying that "company loyalty" may serve as a barrier to substitution. The study of issues concerning problem solving or situational constraints can be summarized as follows: In Michigan, pharmacy size attributes had the expected negative relationship with DPS rates, while in Wisconsin, there was evidence that size had a positive association with DPS rates. Higher DPS rates were associated with rural settings for both states but competition seemed to have a negative effect. In Michigan, the number of products in stock had a negative relationship with DPS rates but the expected incentive to use products stocked (inventory) was not demonstrated clearly in either state. What is written on the prescription order (prescriber "cues") seems to be a more important determinant of product choice than the hypothesized "problem solving" related to inventory. Issues concerning professional or community relationships led to hypotheses of negative relationships between the measures of the service area and the DPS rate. This measure of the importance of community relationships was not demonstrated. The importance of prescriber "cues" was suggested again by a positive association between the number of different br and s prescribed and DPS rates. Prescribing patterns seem to have a dominant influence on product choice as compared to solving problems such as using inventory or maintaining community relationships. Though the exact determinants of variation in substitution rates cannot be specified, future regulatory endeavors to promote the substitution of less costly generically equivalent products should not ignore the importance of pharmacy characteristics or their potential importance under different regulatory provisions.PhDPublic healthUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/158239/1/8116223.pd