Applying quantitative bias analysis to estimate the plausible effects of selection bias in a cluster randomised controlled trial: secondary analysis of the Primary care Osteoarthritis Screening Trial (POST)

Table 1 New data from the categorised trial outcome for control and intervention arms for each follow-up time point

Follow-up time	3 months		6 months		12 months
	Intervention	Control	Intervention	Control	Intervention	Control
High pain	162	253	159	236	136	215
Low pain	221	448	215	444	232	429
Total	383	701	374	680	368	644
Potentially eligible before recruitment	3041	4238	3041	4238	3041	4238
Crude OR for treatment effect (95% CI)	1.30 (1.01, 1.67)		1.39 (1.07, 1.80)		1.17 (0.90, 1.53)

ISSN: 1745-6215