Table 5.

Use of causal wording by study design, type of exposures examined, and whether the first author affiliation was from a country in which English is an official language.

	Number of studies in which causal language was used
	Abstract objectives/hypotheses	Title/abstract (other than objectives/hypotheses)	Objectives/hypotheses in main text	Main text other than objectives/ hypotheses
Observational study design
Cross-sectional (N = 117)	5	37	11	89
Cohort (N = 63)	8	31	17	58
Case-control (N = 19)	3	11	9	17
Nested case control (N = 1)	0	0	0	1
First author affiliation from a country with English as an official language
Yes (N = 82)	6	36	21	82
No (N = 118)	10	43	16	95
Type of exposure variables
Intervention only (N = 3)	1	3	1	3
Time-varying only (N = 12)	1	4	3	7
Time-invariant only (N = 6)	0	2	1	3
Intervention and time-varying (N = 27)	7	14	7	25
Intervention and time—invariant (N = 11)	1	3	1	8
Time-varying and invariant (N = 37)	2	10	6	24
All three types (N = 104)	4	43	18	95