[hazard]

If only the authors had considered this...

> Noncausal mechanisms, including socioeconomic status and reverse causation bias, have been proposed as contributors to the KIHD findings (Kivimaki et al., 2015). Although differences in socioeconomic status may influence sauna access and opportunities for use, the robust dose-dependent associations observed between sauna bathing and sudden cardiac death, coronary artery disease, and cardiovascular events in the KIHD studies are indicative of genuine inverse associations (Laukkanen et al., 2015a). Furthermore, the KIHD studies were conducted in Finland, where sauna use is deeply rooted in the culture, and saunas are readily accessible (Laukkanen et al., 2015a). Similarly, whereas reverse causation bias figures prominently in observational studies and is a valid concern when investigating links between cardiovascular disease and lifestyle, the KIHD findings were adjusted for potential biases, including lifestyle factors such as socioeconomic status, physical activity, and cardiorespiratory fitness (Laukkanen et al., 2015a).