The phrase "a substantial problem in" is correct and usable in written English.
It can be used when discussing significant issues or challenges within a specific context or field.
Example: "There is a substantial problem in the healthcare system that needs immediate attention."
Alternatives: "a significant issue in" or "a major challenge in".
But, he warned, "It does leave us with a substantial problem in the next year -- as we have to make these major infrastructure investments -- about where we're going to get the capital".
Low patient adherence is a substantial problem in therapy.
Malaria remains a substantial problem in this region and efforts to minimise transmission should be considered in future house planning.
Corneal endothelial dysfunction is a substantial problem in FECD, and it is accompanied by visual disturbance which provides a major indication for corneal transplantation surgery [138].
Nitrogen (N) leaching is considered a substantial problem in South China vegetable production because of the heavy rainfall and the excessive application of N fertilizer, but quantitative data and effective countermeasures are lacking.
Water scarcity is already a substantial problem in today's world.
However, resistance to chemotherapy is a substantial problem, reflected in subsequent presentations with recurrences.
The current literature, however, suggests that nonadherence to and nonpersistence on DMARD therapy is a substantial problem, ranging in occurrence from 20%to70%0% [ 10, 14- 23].
Antimicrobial sensitivity patterns indicate that resistance is a substantial problem among enterobacteria in Lusaka (Table).
In one in four cases there was a "clinically important delay" before the patient was seen by a consultant, access to CT and MRI scanning is a "substantial problem" at many hospitals and in one in five hospitals "do not attempt resuscitation" orders were signed by "very junior trainee doctors".
Because of the high cost of so many films, many studios have been eager to thwart film piracy, which is a substantial problem for American films in Asia.
