Most part of scientific letterature shows important difference of ethnic/cultural perception of work.I suggest you adapt some test to Nigerian population, and then develop a new study.  In this way you can justify the needing to develop a new test.

There are many different test:

- OPRA

- CUIDA

- GHQ

- JCI

- JCQ (Karasek)

- JDS

- JSQ

- M_DOQ10

etc.. For any information you can contact me directly. 

Wishes

Thank you very much, Assoc Prof Florent Lheureux and Pietro Crescenzo. Your respective contributions provided some meaningful insights for me. I will return to you (separately) when am done with the respective advises you people gave me. Once again, thank you! ... GANDI