While the placebos can affect how the person feels, studies have suggested that they do not have any significant impact on the underlying illnesses. A major review of more than 150 different clinical trials involving the placebos have found that the placebos did not have any major clinical effects on the illnesses. Instead, the placebo effect showed a small influence on the patient-reported outcomes, particularly of the perceptions of nausea and pain.However, another review that was conducted about 10 years later found that in the similar populations, both the placebos and the treatments had similar effects. The authors concluded that the placebos when used appropriately, could potentially benefit the patients as part of the therapeutic plan.