Opioid overdose deaths, caused by both prescription painkillers and illegal narcotics, have grown rapidly in the past few years. According to recent articles in the Boston Globe, the problem is particularly severe in New England, including Massachusetts. However, community burdens are grossly unequal.
A recent Globe article indicated that some small towns, including Aquinnah on Martha’s Vineyard, have major problems. However, the Globe lacks math skills. Its reporters and editors failed to consider whether data they presented had statistical significance. For Aquinnah, numbers of events were so small that there was little significance. Lack of significance occurred with 254 of the 351 Massachusetts cities and towns.
Rates of opioid overdose deaths varied greatly among the 97 communities for which data had strong statistical significance. For the four years of data now available, calendar 2012 through 2015, the statewide average was 162 deaths per year per million residents. Communities can be compared by the differences between their opioid overdose death rates and the state average. Expressing those differences in units of confidence intervals gives a statistically weighted picture when comparing communities.
Considered that way, the three least hazardous communities were Brookline, Needham and Wellesley:
difference, in intervals
From 2012 through 2015, Brookline experienced a rate of 17 opioid overdose deaths per year per million residents–from a total of 4 events. Statistics gave 17.0 as a 95%-confidence interval for its rate. The Brookline rate was 8.5 confidence intervals lower than the state average: a very significant difference.
At the other end of the scale, the three most hazardous communities were Lynn, Quincy and New Bedford:
difference, in intervals
From 2012 through 2015, Lynn experienced a rate of 357 opioid overdose deaths per year per million residents–from a total of 125 events. Statistics gave 62.9 as a 95%-confidence interval for its rate. The Lynn rate was 3.1 confidence intervals higher than the state average: a very significant difference.
Massachusetts opioid overdose deaths concentrated in 17 high-hazard communities: Lynn, Quincy, New Bedford, Fall River, Worcester, Lowell, Haverhill, Brockton, Everett, Revere, Weymouth, Pittsfield, Taunton, Malden, Wareham, Stoughton and Carver. With 18 percent of the state population, they experienced 33 percent of the events.