"The medical missionary workers are to be purified, sanctified, ennobled. They are to rise to the highest point of excellence. They are to be molded and fashioned after the divine similitude. Then they will see that health reform and medical missionary work are to be bound up with the preaching of the gospel. 8T 168.4"
"For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren."
Both passages discuss being molded or conformed to a divine image. Romans 8:29 speaks of being conformed to the image of Christ, while the EGW passage speaks of medical missionary workers being molded after the divine similitude. The connection is thematic and related to spiritual transformation.