The phrase "are problematic to compare" is correct and usable in written English.
It can be used when discussing issues or challenges related to making comparisons between two or more items, concepts, or situations.
Example: "The two theories are problematic to compare due to their fundamentally different assumptions."
Alternatives: "difficult to compare" or "challenging to compare".
In addition, we found that the probe expression levels, typically expressed as fold difference between probe and mismatch probe are problematic to compare between ORFs with differing GC content.
It is important to mention that catalytic efficiencies are problematic to compare, since the various enzymes were probed at different chlorite concentrations, pH-values, and temperatures.
Carole Puls, a spokeswoman for Eli Lilly and Co., which makes Zyprexa, said it was problematic to compare large groups of medications because there are differences between the drugs in each class.
Unfortunately, these measures are not defined by standard accounting rules, and so they can be problematic to compare across firms.
The fact that ACA plan premiums have been much too low to cover insurer expenses is another reason that it is problematic to compare face value premiums of ACA plans with pre-ACA individual market plans.
But in my opinion, it is problematic to compare those earlier reports with this UK-based study because birds, especially owls, have vastly different uses and cultural significances in India and Indonesia, so demand for owls in those countries stems from a variety of cultural uses (i.e.; traditional "medicine") that are not comparable to the UK owl trade.
While it can be problematic to compare our standards of justice and equality to those of another historical setting, let's just say that if we look closely, Yusuf's spiritual tradition vs. degenerate modernity binary is a little more complicated than he wants it to be.
It is problematic to compare the numbers of DE-sequences in various studies differing in experimental design and methodology.
Due to the differences in social welfare systems and medical health systems, it might be problematic to compare our results with those of other countries.
