Box 1.

Search strategy (example taken from the MEDLINE database)

“exp*. FAMILY PRACTICE OR exp. PRIMARY HEALTH CARE OR exp. PHYSICIANS, FAMILY OR exp. COMMUNITY HEALTH SERVICES OR “general practi*”† OR GP OR (primary ADJ2‡ care) OR (family ADJ2 physician*) OR (family ADJ2 practi*) OR (family ADJ2 doctor*) OR (community ADJ2 (service* OR care)) OR (general ADJ2 physician*)”

AND

“exp. NEOPLASMS OR neoplasm* OR cancer* OR carcinoma* OR malignan* OR lesion* OR tumo?§r”

AND

“educat* OR exp. EDUCATION, MEDICAL, CONTINUING OR skill* OR train* OR teach*

AND

(earl* ADJ2 diagnos*) OR (earl ADJ2 detect*) OR (delay* ADJ2 diagnos*) OR (delay* ADJ2 detect*) OR (suspicious OR suspect*) OR (earl ADJ2 recog*) OR (delay ADJ2 recog*) OR (present* ADJ2 symptom*) OR (delay* ADJ2 consult*)”

^*exp. = exploded thesaurus term – picks up all articles that contain the particular terms as a keyword.

^†truncation – picks up various different word endings.

^‡adj = adjacent – picks up words next to each other in a document (adj3 = picks up words that have up to 3 words in between them).

^§? = picks up alternative spellings.