Words similar to difficult

Example sentences for: difficult

How can you use “difficult” in a sentence? Here are some example sentences to help you improve your vocabulary:

Hence, the evidence accumulated has come mostly from epidemiological studies, but it is notoriously difficult to remove all confounding factors from these studies.
Because randomized cancer screening trials are very expensive and sometimes difficult to implement, observational cancer screening studies can play an important role in estimating the efficacy of cancer screening during early phases of evaluation of the screening test.
Even the formidable Duke of Edinburgh was heard to remark ruefully on an official visit to Papua New Guinea that it was very difficult to maintain a stiff upper lip when one was constantly being introduced as Whitefella Blongum Kween.
To balance between therapeutic sedation to reduce burdensome distress in the terminal and dying phase and sedation in patients who voluntary request sedation "to die in sleep" is a difficult challenge.
By making intrinsically difficult comparisons nearly impossible, dealers augment their power over the market.