Table 1.

Type of study designs, common data collection methods, type of bias, and adjusting strategies

Study design	Data collection method	Type of bias	Overcoming strategy
Observational	Self-administered questionnaire, surveys, or interviews	Social desirability	Conduct internal or external validation study
			Apply Marlowe–Crowne Social Desirability Scale or Martin–Larsen Approval Motivation score
		Recall	Use memory aids or diaries Interview a subsample of participants prior to initiating the study (validated subsample)
Observational/experimental	Laboratory tests	Systematic errors	Conduct calibration study
		Random errors	Apply statistical adjusting method (eg, simulation–extrapolation, regression calibration, Bayesian approaches) Replicate measurements
	Clinical examination/diagnostic tests	Confirmation	Make multiple and independent checks
			Introduce training and education programs