Predictors of generic substitution: The role of psychological, sociodemographic, and contextual factors

BackgroundEscalating pharmaceutical costs have become a global challenge for both governments and patients. Generic substitution is one way of decreasing these costs.ObjectiveThe aim of this study was to investigate factors associated with patients' choice between generic drugs and innovator drugs.MethodThe survey was conducted in June 2013, 1000 people from across Poland were chosen as a representative population sample. The outcome (a preference for generics/a preference for innovator pharmaceuticals/no preference) was modeled by multinomial logistic regression, adjusted for several variables describing patients' sensitivity to selected generic features (price, brand, and country of origin), to third-party opinions about generics (information on generics in the mass media, opinions of health professionals (i.e. physicians, pharmacists), relatives/friends), as well as patients' personal experiences and income per household.ResultsThe results supported the predictive capacity of most independent variables (except for patient sensitivity to the country of origin and to the information on generics in the mass media), denoting patients' preferences toward generic substitution. Patient sensitivity to recommendations by physicians, generic brand, and household income were the strongest predictors of the choice between generic and innovator pharmaceuticals (P < 0.001). The probability of choosing generics over innovator drugs was significantly higher among respondents with the lowest income levels, in those who were indifferent to generic brand or their physician's opinion, as well as in respondents who were sensitive to recommendations by pharmacists or attached a greater value to a past experience with generics (their own experience or that of relatives/friends).ConclusionIn consideration of the foregoing, awareness-raising campaigns may be recommended, supported by a variety of systemic solutions and tools to encourage generic substitution.