Negative Amazon reviews of scented candles may indicate the number of covid-19 cases in the community and could even predict future infection spikes.
Viral Twitter posts have suggested that Amazon reviews for highly scented products could highlight the extent of anosmia, or a loss of smell, among the population, a key covid-19 symptom. However, some pointed out the purchase of products like candles may be skewed towards Christmas, when people are more likely to have a cold or flu, which can also affect our sense of smell.
To learn more, at Northeastern University, Massachusetts, and his colleagues analysed 9837 Amazon reviews for four best-selling scented candles produced by the brand Yankee Candle, left between September 2018 and December 2021.
Advertisement
They noted the number of reviews that mentioned the scented candles had no discernible smell. A model then compared the previous number of reported covid-19 cases in the US with the number of reviews complaining the scented candles were odourless.
The research 鈥渟tarted out as a joke鈥�, says Beauchamp, however, the team found a link between covid-19 cases and negative candle reviews.
For every 100,000 new covid-19 cases a week in the US over the study period, the number of Yankee Candle reviews saying the product had no smell went up by 0.25 percentage points. A statistical analysis revealed this link wasn鈥檛 a chance finding.
The connection also persisted despite the study covering the beginning of the omicron wave in the US, spanning December 2021 to February 2022. Omicron less commonly causes anosmia compared with previous variants of the coronavirus. The link also still stood after the researchers accounted for the other seasonal illnesses that can affect sense of smell.
A subsequent research update, which hasn鈥檛 been peer-reviewed, includes data from September 2018 to June 2022. Unlike the original analysis, the update suggests candle reviews may not just lag covid-19 cases, but could even predict an infection spike.
鈥淚t鈥檚 often the case that when you increase your data, your results can change just due to increased data to work with,鈥� says Beauchamp.
鈥淢y hypothesis is that this shift in which leads and which lags [in terms of covid-19 cases and negative Amazon reviews] is鈥� due to the official case count increasingly lagging actual cases鈥�.
Monitoring scented candle reviews could track covid-19 cases as regular testing winds down worldwide, he says.
鈥淓ven if this study alone can鈥檛 prove any causal connection, it builds a solid little piece of evidence that the lack of smell was indeed a widespread symptom during the peak of the covid pandemic,鈥� says at IT University Copenhagen, Denmark.
Reference:
