Table 2 EPHPP tool domain ratings

Study

Global rating

Selection bias

Study design

Confounders

Blinding

Data collection methods

Withdrawals and dropouts

Strong: 1 ≤ weak rating

Weak: > 1 weak rating

Strong: participants more likely to represent the target population with > 80% participation.

Weak: less likely to represent the population with < 60% participation.

Strong: randomized/clinical controlled trial

Weak: any design apart from randomized, clinical, case-control, cohort anality, and cohort interrupted time series.

Strong: controlled for at least 80% of relevant confounders

Weak: controlled for less than 60% of relevant confounders.

Strong: outcome assessors unaware of participants’ intervention status AND participants unaware of the research question.

Weak: aware of both.

Strong: valid and reliable data collection methods

Weak: data collection methods both unreliable and invalid.

Strong: greater than 80% follow-up rate.

Weak: follow-up rate of less than 60%.