The phrase "a key theme is" is correct and usable in written English.
You can use it when introducing an important idea or concept that is central to a discussion, analysis, or narrative.
Example: "In the novel, a key theme is the struggle for identity in a changing world."
Alternatives: "an important theme is" or "a central theme is".
A key theme is that attention modulates cortical self-organization and stability.
A key theme is expected to be that early intervention at every stage of life can prevent society having to continue "paying for the costs of failure".
In Ariels portfolios, a key theme is our enthusiasm for businesses competent at minding matters others need but are smart to avoid.
Finally, a key theme is the "Increase of Food Production Yield" without an impact on environmental resources, where a lot of digital and biotechnologies are being applied to solve the growing misalignment between the demand and supply of food.
Nowadays, although Meyer herself claims a key theme is learning to love the bodies we are in, some have viewed The Host as echoing contemporary concerns about the over use of drugs that may calm us down or cheer us up, but subdue our personalities as well as our anxieties.
While the movement's implications have sometimes been interpreted in a very broad way (which may incorporate problem solving in a very generic sense, so called "lateral thinking", and information literacy), a key theme is the importance of argument and argument assessment in educational curricula.
Mr. Bedell's postings on the Internet covered a broad range of topics, but a key theme was Sept. 11.
Miliband said a deal at next month's crunch UN climate talks in Copenhagen on funding for reducing deforestation – a key theme – was "now closer than it's ever been".
Just days prior to the Vice President's remarks, USASI and the Sasakawa Peace Foundation (SPF) co-hosted the 2018 the U.S.-Japan Security and Defense Dialogue Series, where a key theme was coordination and cooperation in the long-standing U.S.-Japan security relationship.
One of the two SCP thrusts was tackling high volume crime such as domestic burglary, where a key theme was to develop local infrastructure and skills to identify the nature of different problems.
Everyone is busy with work, family commitments, and life in general...but a key theme was that we should be taking more time to reflect productively on our lives.
