The effect of direct to consumer television advertising on the timing of treatment

We examine how direct to consumer advertising affects the delay between diagnosis and pharmacological treatment for patients suffering from a common chronic disease. The primary data for this study consist of patients diagnosed with osteoarthritis (N = 18,235) taken from a geographically diverse national research network of 72 primary care practices with 348 physicians in 27 states over the 1999-2002 time period. Brand-specific advertising data were collected for local and network television at the monthly level for the nearest media markets to the practices. Results of duration models of delay to treatment suggest advertising does affect the length of time that patients and physicians wait to initiate therapy. This evidence suggests that these effects may be welfare enhancing in that advertising tends to encourage more rapid adoption among patients who are good clinical candidates for the therapy and leads to less rapid adoption among some patients who are poor clinical candidates.