It might be generally considered but that doesn't make it accurate, IIRC it improved public health quite a bit which continued even after prohibitions repeal.
The notion "Prohibition must have caused a drastic decline in alcohol consumption because deaths from cirrhosis of the liver declined so much" is subjected to serious criticism here:
http://www.nber.org/papers/w9681.pdf
"The U.S. experience with national prohibition of alcohol plays a frequent role in discussions of government policy toward alcohol, drugs and other commodities. Central to this debate is whether, or to what degree, Prohibition reduced consumption of alcohol. Data on alcohol consumption are not available for the Prohibition period, however, so numerous authors have used the cirrhosis death rate to infer the behavior of alcohol consumption. Focusing on comparisons of the pre-Prohibition and early Prohibition periods, these authors have suggested that Prohibition caused as much as a 50% decline in cirrhosis.1
"Existing analyses of Prohibition and cirrhosis are potentially problematic, however. Most analyses have focused on the univariate behavior of cirrhosis and conducted simple comparisons of the pre-Prohibition and Prohibition periods. This approach ignores other Prohibition-era changes in alcohol-control policies, including state prohibitions, wartime prohibition, and increased alcohol taxation. Likewise, the univariate approach fails to account for the many nonpolicy variables that might affect cirrhosis, including social attitudes, income, war, and demographics.
"This paper evaluates the impact of Prohibition on cirrhosis death rates, and it considers the possible implications for understanding the effects of prohibitions generally.
"Section 2 re-examines the relation between cirrhosis and alcohol consumption. Both biomedical research and comparisons across countries or time periods suggest alcohol consumption is an important determinant of cirrhosis. Using cirrhosis to infer Prohibition’s impact on alcohol consumption, however, assumes that short-term fluctuations in cirrhosis are reasonable proxies for short-term fluctuations in alcohol consumption. We document that the time-series variation in alcohol consumption explains much of the time-series variation in cirrhosis, but the relation is far from perfect. More importantly, various aspects of the relation need to be accounted for if the behavior of cirrhosis is to suggest conclusions about alcohol consumption.
"Section 3 begins our examination of Prohibition’s impact on cirrhosis. We show that cirrhosis was lower during Prohibition than in most years before or after, which makes a prima facie case that Prohibition reduced cirrhosis. Further examination, however, suggests caution in drawing this conclusion. First, there have been substantial fluctuations in cirrhosis outside the Prohibition period, which suggests that factors other than Prohibition should be considered before concluding that Prohibition caused the low level during Prohibition. Second, cirrhosis did not jump dramatically upon repeal of Prohibition, which fails to suggest an important effect of Prohibition. Most importantly, cirrhosis had fallen to its low, Prohibition level by the time Prohibition began, which means Prohibition did not cause the low level of cirrhosis at the beginning of Prohibition.
"Section 4 then presents regressions of state-level cirrhosis death rates on measures of state prohibition, constitutional prohibition, and other variables. These regressions suggest that state-level prohibition had only a small impact on cirrhosis; instead, one or more aggregate factors caused a major decline in cirrhosis during the 1917-1919 period. Pre-1920 federal antialcohol policies might have contributed to this decline, but other factors were likely important influences as well. Whatever caused the pre-1920 decline, constitutional Prohibition lowered the cirrhosis death rate by about 10-20%....
"We conclude by relating our results to the literature on the price-elasticity of the demand for alcohol. That literature offers a broad range of elasticity estimates, from virtually zero for certain population subgroups to well in excess of -1.0 overall.32 If the true elasticity is in the middle of this range, the small response of cirrhosis to Prohibition is surprising given the conventional view that alcohol prices rose substantially during Prohibition. The estimates in Table 4 above indicate an elasticity of cirrhosis with respect to alcohol consumption of 0.4-0.7, and Thornton (1991) suggests that alcohol prices rose by about 500%. This implies that cirrhosis should have fallen to almost nothing, rather than declining 10-20% as estimated above.
"One possible reconciliation is that the relevant elasticity is in fact quite low. The proxy for alcohol consumption considered here is plausibly a better measure of heavy consumption than of moderate consumption. Theory does not suggest that heavy or addictive consumption is necessarily inelastic (Becker and Murphy 1988), but there is evidence from micro data suggesting that heavy consumption of alcohol is in fact virtually price inelastic (Manning, Blumberg, and Moulton 1995).
"A second possible reconciliation is that the standard view about alcohol prices is inaccurate. The conventional wisdom is based on data in Warburton (1932) and Fisher (1928, 1930); reexamination of these data suggests a more nuanced picture.
"The first problem with the standard view is that it neglects the behavior of the overall price level. Warburton's data compare prices between 1911-1915 and 1926-1930, while Fisher's compare prices between 1916 and 1928. Both authors examine the behavior of nominal prices, yet the price level increased by approximately 75 per cent between these two periods (Bureau of the Census (1975), p. 211). Thus, the raw data presented by Warburton and Fisher overstate the increase in the relative price of alcohol.
"In addition, Warburton presents a broad range of prices for the Prohibition period, and the lowest prices reported suggest that, even ignoring inflation, some alcoholic beverage prices fell relative to the pre-Prohibition period. This does not prove consumers paid less on average for alcohol, but they faced an incentive to buy at the lowest prices and then stockpile the quantities purchased. The available data do not allow computation of the average price actually paid, and the extremely high prices reported in many cases by both Warburton and Fisher allow for the possibility that the average price in fact rose. But the magnitude of this rise is undoubtedly less than they asserted, and it is possible prices failed to rise substantially overall. If prices did not increase very much, there is no puzzle in the failure of consumption to fall substantially.
"This last “explanation” raises the question of why prices would not have risen more strongly. One possibility is that because black market suppliers faced low marginal costs of evading alcohol taxes and cost-increasing regulation, the net effect of prohibition on costs was modest (Miron 2003).
"A second hypothesis is that Prohibition had little chance of being effective because of the numerous avenues for evasion (Merz 1930, pp.65-71). Under Prohibition, physicians, druggists and manufacturers of proprietary medicines could receive licenses to prescribe and dispense liquor for “medicinal” purposes. The production of beer for the purpose of making near beer remained legal, as did the production of industrial alcohol.33 Both exceptions to Prohibition allowed for substantial diversion to consumption. Smuggling across the vast borders of the U.S. provided another way to circumvent Prohibition. And perhaps most importantly, home production and small scale production of alcohol proliferated, thereby straining even the most vigorous enforcement efforts.
"A third possibility is that Prohibition created a forbidden fruit effect, thereby shifting preferences for alcohol and partially offsetting the depressing effect on demand of higher prices. This hypothesis receives anecdotal support in some contexts, and accounts of drinking behavior during Prohibition are consistent with such an effect (e.g., the term “roaring 20s”). Without more detailed evidence, however, one cannot interpret the results here as a strong indication of such an effect..."