Strengths and limitations
EVENTS, MINOR
This study is based on a total population of employed Swedes with virtually no missing data, thus the sample is highly representative of the Swedish work force. The Swedish National Prescribed Drug Register contains information on all prescribed drugs dispensed at a Swedish pharmacy and thus has a good coverage of purchases of the drugs in focus in the present study. Information on redeemed prescribed sedatives and anxiolytics from several years before and after exposure to downsizing were utilized, making it possible to capture changes within different phases of the downsizing process. By examining different types of drugs this study can also contribute to a better understanding of potential short- and long-term effects of downsizing.Due to the long period with available data we were able to utilize exposure to downsizing occurring in four different 12-month periods, making the results less sensitive to conditions of the labor market in one specific year. Hence, the associations between downsizing and purchases of psychotropic drugs are not likely to be influenced solely by the recession in 2008, although more major downsizing events occurred shortly after the economic downturn. Furthermore, dividing the exposed group into different categories based on their employment situation the year after downsizing made it possible to investigate the heterogeneity in purchases among different exposed groups. Since information on exposure and outcome is based on register data, this study should furthermore not be influenced by, e.g., recall bias and common method bias.However, using only register based information on downsizing infers a risk of misclassification. From the Statistics on Dynamics of Enterprises and Establishments (DEE) register we only know whether a workplace reduced their staff or not between two subsequent years but not whether the person we defined as being exposed to downsizing was directly affected by staff reductions at that workplace. The downsizing could have been restricted to specific units at the workplace. On the contrary there might be people who have been classified as non-exposed although they might work in a unit heavily targeted with major staff reductions. Employees classified as unexposed could also have been exposed to minor downsizing. This type of misclassification would result in an underestimation of any effect of downsizing on mental health. Moreover, we have used the most commonly applied definition of major downsizing, but according to our knowledge, a standard definition of major downsizing is lacking. Although previous studies have shown stronger associations between major downsizing and health than for minor downsizing [Regarding purchases of prescribed sedatives and anxiolytics, a couple of limitations are worth noting. Studying the number of purchases made is somewhat crude as it does not capture the variation in dose-levels, meaning that differences in defined daily dosages are not detected. However, results regarding the number of purchases per person did not differ much from the trends of any purchases made and the problem of non-adherence would persist even if a more detailed measure was applied. Furthermore, the people captured in this study might be what Last and Adelaide call the tip of the iceberg [