Researchers conducted a case-control study to identify risk factors for kidney cancer. They asked 50 cases and 50 controls about 100 different exposures and personal characteristics, and calculated the odds ratio for kidney cancer for each risk factor. They found statistically significant odds ratios with 2 factors: coffee intake (p=.03) and cell phone usage (p=.04). The authors should conclude that:
Coffee and cell-phone usage increase the risk of kidney cancer.
The risks of coffee and cell-phone usage have been exaggerated due to the use of odds ratios.
These associations are likely chance findings.
The study had insufficient statistical power.
Coffee and cell-phone are statistically significant but not clinically significant risk factors for kidney cancer.