Is assessment of oral health-related quality of life burdensome? An item nonresponse analysis of the oral health impact profile

Table 2 Prevalence of OHIP missingness (%) for the overall participants and for subsets of participants based on variables of interest in two studies with and without supervision

	Data collection without supervision			Data collection with supervision
	Participants with missing OHIP information ^a	Missing items in all participants ^b	Missing items in participants with missing OHIP information ^c	Participants with missing OHIP information ^a	Missing items in all participants ^b	Missing items in participants with missing OHIP information ^c
Variables of interest
Item location
First half of the questionnaire	13.4	2.3	17.1	5.2	0.3	5.9
Second half of the questionnaire	8.5	2.5	29.0	5.4	0.3	6.3
Age^†
Younger	11.3	1.0	8.7	6.8	0.2	3.1
Older	23.1	3.7	16.2	11.9	0.4	3.4
Gender
Male	14.2	1.4	9.8	8.8	0.3	3.4
Female	19.9	3.2	15.8	9.7	0.3	3.3
OHRQoL impairment^†
Less	14.9	2.6	17.6	5.6	0.2	3.7
More	20.4	2.1	10.4	13.2	0.5	3.4

Refer to the definition listed under data analysis (a) – (c) for column labels:
^aNumber of participants with any missing OHIP items divided by the total number of participants
^bNumber of missing items divided by the total number of items among all participants
^cNumber of missing items divided by the total number of items among participants with any missing OHIP items
^†Median split is applied

ISSN: 1472-6831