Table 5.

Results from the psychometric analyses of part Ix of the COS-CRC

COS-CRC Part Ix: item order in the questionnaire	Subscales and misfit	Observed	Expected	Gamma sd	Probability of fit to the Rasch modela	Item difficulty	Single or ‘poor’ item
47. Discomfort with having bowel emptied	Perceived burden of bowel preparation	0.763	0.736	0.040	0.49617	− 1.08
48. Feeling of having a lesion on rectum	Perceived burden of bowel preparation	0.830	0.775	0.047	0.24357	0.79
49. Stinging feeling in the rectum	Perceived burden of bowel preparation	0.822	0.759	0.047	0.18284	0.85
50. Pain during emptying of bowel	Perceived burden of bowel preparation	0.754	0.792	0.047	0.42003	0.86
51. Feeling of a rash on backside	Perceived burden of bowel preparation	0.805	0.759	0.047	0.33519	0.82
52. Feeling stranded at home during emptying of bowel	Perceived burden of bowel preparation	0.661	0.737	0.041	0.06132	− 1.98
53. Worried about drinking other fluids during emptying of bowel	Perceived burden of bowel preparation	0.605	0.736	0.046	0.00444	0.34	‘Poor item’
54. Anxious about having one or more polyps	Knowledge of having colorectal polyps	0.936	0.936	0.029	0.98862	− 2.88
55. Confused about what it means to have one or more polyps	Knowledge of having colorectal polyps	0.936	0.936	0.029	0.98862	3.00
56. Discomfort during the colonoscopy	Negative experiences of the colonoscopy	0.742	0.739	0.034	0.91764	− 1.17
56. Discomfort during the colonoscopy	Negative physical experiences of the colonoscopy	0.900	0.870	0.027	0.26895	− 0.77
57. Felt defenseless lying on the examination table	Negative experiences of the colonoscopy	0.840	0.735	0.038	0.00567	− 0.23
57. Felt defenseless lying on the examination table	Negative emotional experiences of the colonoscopy	0.850	0.868	0.025	0.49037	− 0.53
58. Felt vulnerable lying on the examination table	Negative experiences of the colonoscopy	0.854	0.735	0.038	0.00188*	− 0.19
58. Felt vulnerable lying on the examination table	Negative emotional experiences of the colonoscopy	0.894	0.871	0.025	0.36890	− 0.46
59. Pain during the colonoscopy	Negative experiences of the colonoscopy	0.598	0.742	0.035	0.00004**	− 0.67
59. Pain during the colonoscopy	Negative physical experiences of the colonoscopy	0.855	0.860	0.026	0.85238	0.06
60. Humiliation lying on the examination table	Negative experiences of the colonoscopy	0.698	0.727	0.043	0.50161	0.45
60. Humiliation lying on the examination table	Negative emotional experiences of the colonoscopy	0.844	0.856	0.030	0.69602	0.59
61. The examination was a harsh experience	Negative experiences of the colonoscopy	0.786	0.742	0.040	0.27558	0.01
61. The examination was a harsh experience	Negative physical experiences of the colonoscopy	0.852	0.871	0.027	0.47659	1.28
62. Lying on the examination table overstepped my boundaries	Negative experiences of the colonoscopy	0.684	0.725	0.046	0.37364	0.60
62. Lying on the examination table overstepped my boundaries	Negative emotional experiences of the colonoscopy	0.856	0.854	0.031	0.96742	0.95
63. Felt exposed lying on the examination table	Negative experiences of the colonoscopy	0.737	0.726	0.046	0.81139	0.58
63. Felt exposed lying on the examination table	Negative emotional experiences of the colonoscopy	0.878	0.852	0.031	0.40937	0.87
64. Regrets having participated in the screening programme	Regret participation	N/A	N/A	N/A	N/A	N/A	‘Single item’

^aBenjamini-Hochberg rejects all p-values < 0.0033 to control the FDR at 0.05 and < 0.0002 to control the FDR at 0.01

^* < 5% false discovery rate (FDR), ** < 1% FDR