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The first column of Table 2 shows estimates for the entire population (copied from Table 1). The coefficients of the three drug-vintage variables (lines 11, 12, and 13) indicate differences between the mortality rates of people using drugs of different vintages. By combining these coefficients with the average mortality rate (line 3) and the vintage distribution of drugs (lines 7-10), we can infer the (levels of) mortality rates of people using drugs of different vintages.

The vintage-specific mortality rates are shown in lines 14-17 of Table 2 and plotted in Figure 4. The estimated mortality rates are strictly declining with respect to drug vintage. For pre-1970 drugs, the estimated mortality rate is 4.4%. The mortality rates for 1970s, 1980s, and 1990s drugs are 3.6%, 3.0%, and 2.5%, respectively. The differences in mortality rates are highly statistically significant (p-value < .0001). http://asthma-inhalers-online.com/buy-generic-ventolin-online.html

We can use these estimates to compare the actual mortality rate in the ASES population (resulting from the actual vintage distribution of drugs) to what the mortality rate would have been, given alternative hypothetical vintage distributions of drugs. We consider two such alternative distributions:
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• P0ST1970 = 0%: this would have characterized the distribution of drugs in 1970

• The vintage distribution of U.S. Medicaid Rx’s in 2000

The results of these calculations are shown in Figure 5. The actual mortality rate is about 16% (3.7% vs. 4.4%) lower than it would have been if all of the drugs utilized in 2000 had been pre-1970 drugs. There would have been almost 3800 more deaths in the ASES population during 2000-2002 if all of the drugs utilized in 2000 had been pre-1970 drugs. This suggests that new drugs introduced during 1970-2000 reduced the mortality rate by about 0.58% (= (1 / 30) * ln(4.4% / 3.7%)) per year.

I would like to compare this figure to time-series mortality data for Puerto Rico during the period 1970-2000. I don’t have time-series data on the age-adjusted mortality rate of Puerto Rico during this period, but I do have data on the age-adjusted mortality rate of the U.S. during the period 1979-1998 (see Figure 6).11 The age-adjusted mortality rate of the U.S. declined at an annual average rate of 0.71% during the period 1979-1998 (and, due to the large jump between 1979 and 1980, it declined at an annual average rate of 0.92% during the period 1980-1998). Moreover, in both Puerto Rico and the U.S., life expectancy increased much more rapidly in the 1970s than it has done since 1980.12 Therefore, our estimates’ implication that new drugs introduced during 1970-2000 reduced the mortality rate by about 0.58% per year is not implausible. At the same time, the estimates imply that the introduction of new drugs accounted for a significant fraction of the long-run decline in Puerto Rican mortality.

Category: EFFECT OF DRUG VINTAGE / Tags: Clinical studies, myocardial infarction, survival rates