This study assessed the reliability and validity of the Child Oral Health Impact Profile–Short Form 19 (COHIP-SF 19) from the validated 34-item COHIP.
Participants included 205 pediatric, 107 orthodontic, and 863 patients with craniofacial anomalies (CFAs). Item level evaluations included examining content overlap, distributional properties, and use of the response set. Confirmatory factor analysis identified potential items for deletion. Scale reliability was assessed with Cronbach's alpha. Discriminant validity of the COHIP-SF 19 was evaluated as follows: among pediatric participants, scores were compared with varying amounts of decayed and filled surfaces (DFS) and presence of caries on permanent teeth; for orthodontic patients, scores were correlated with anterior tooth spacing/crowding; and for those with CFA, scores were compared with clinicians’ ratings of extent of defect (EOD) for nose and lip and/or speech hypernasality. Convergent validity was assessed by examining the partial Spearman correlation between the COHIP scores and a standard
The reduced questionnaire consists of 19 items: Oral Health (five items), Functional Well-Being (four items), and a combined subscale named Socio-Emotional Well-Being (10 items). Internal reliability is ≥0.82 for the three samples. Results demonstrate that the COHIP-SF 19 discriminates within and across treatment groups by EOD and within a community-based pediatric sample. The measure is associated with the
Reliability and validity testing demonstrate that the COHIP-SF 19 is a psychometrically sound instrument to measure oral health-related quality of life across school-aged pediatric populations.
Oral health-related quality of life (OHRQoL), a multidimensional construct that taps an individual's well-being, is increasingly being recognized as an integral part of general health (
Given these varied applications, it is not surprising that considerable effort has been invested in developing instruments designed to measure OHRQoL (
The Child Perceptions Questionnaire (CPQ11-14) was the first instrument created for school-aged children using clinical and community samples (
Recently, the Pediatric Oral Health-Related Quality of Life (POQL) was created as a brief measure of children's OHRQoL (
Another OHRQoL measure for school-aged children is the Child Oral Health Impact Profile (COHIP). This 34-item instrument was initially validated with a diverse sample of treatment-seeking school-aged children (ages 8-17) who represented varying oral conditions, health systems, and ethnicities. Creating the COHIP was a multistage process that included psychometric testing, descriptive studies of patient populations, caregiver proxy, and child comparisons, as well as construct validity testing with other psychometric instruments related to well-being and psychological factors (
After sufficient use, developing short forms (SFs) of QoL measures is both advantageous and recommended. Long survey instruments can be burdensome to patients/participants and demand excessive personnel time especially when these participants may be expected to complete multiple survey instruments and health questionnaires. Furthermore, shortened measures are easier to score and interpret and may expand the application of such assessments in clinical research. Generic QOL instruments, such as the SF Health Survey (SF 12) and the World Health Organization Quality of Life instrument, have been reduced (
While shortening instruments for ease of use has practical advantages, it is important that the reduced scale maintains appropriate psychometric properties. Yet, there are no precise guidelines on the ideal number of items to target or on the best method for such item reduction. Some reports recommend keeping at least four items per domain to control for random error and to allow within-domain analysis (
The goal of the present study is to explore a possible reduction in the number of items on the 34-item COHIP to create a shorter measure for multiple purposes (e.g., needs assessment and clinical research) that retains its strong reliability and validity properties. In this paper, we will describe the process, decision-making, and psychometric testing involved in creating the COHIP–SF.
Convenience samples were utilized in conjunction with clinical research efforts at pediatric dental (ped), orthodontic (ortho), and CF sites across various locations in the United States. Data were collected in accordance with Institutional Review Board (IRB) specifications at the sites.
Researchers at University of California (UC) Davis are conducting a population-based health study of agricultural workers in Mendota, California – a small, rural community in the San Joaquin Valley. The UC Davis team invited the UC San Francisco's (UCSF's) National Institutes of Health-funded Center to Address Disparities in Children's Oral Health to collaborate with them and add a dental component to their Mexican Immigration to California: Agricultural Safety and Acculturation study. This study of caries status and OHRQoL of children of agricultural workers strives to uncover the magnitude, extent, and impact of children's oral health problems from clinically determined and self-reported perspectives. A house-to-house enumeration identified households comprised of agricultural workers from which 958 families were randomly selected. Of the random sample, 340 (35 percent) did not meet the UC Davis’ inclusion criteria (primary householder age <55 years), and 196 (20 percent) declined to participate. The remaining 421 eligible house-holds consented to participate. The inclusion criteria for the UCSF OHRQoL study included children ages 7-17 who resided in the subset of the 421 households selected by UC Davis for their population-based study.
This project was reviewed and approved by the UCSF Committee on Human Research. Informed consent from each child's parent was obtained prior to administration of the COHIP, parent interview, and dental exam. Each child (seven and older) gave assent prior to administration of the COHIP and dental exam. Spanish and English consent forms were available and a bilingual research staff member facilitated the consent and assent. The questionnaire was printed in English and Spanish and given according to each participant's preference. After explaining the instructions, a brief pretest was given to determine if the child had sufficient literacy level to complete the instrument. As compensation for their time and expression of appreciation, families received a $15 gift certificate to a local food market.
The dental exams followed universal infection control guidelines and were performed in a portable chair with a fiber optic light. One dentist, trained and experienced as a research dental examiner [previously a National Health and Nutrition Examination Survey IV (NHANES IV) study examiner], completed all dental exams. The dental exam yielded markers of clinical oral health including decayed and filled tooth surfaces (DFS index) for permanent teeth and dfs index for primary teeth in children in accordance with NHANES standards. The parental interview also provided the parent's assessment of the child's overall health: “In general, how would you describe the condition of your child's overall health?” Responses were rated using a five-point scale (from poor to excellent) with higher scores reflecting better health.
A nonrandom, convenience sample of children, ages 9-17 years, was recruited in the postgraduate clinic at New York University (NYU) College of Dentistry specifically to examine OHRQoL. The participants consisted of “new patients” who presented for consultation, treatment planning, or initial bonding.
The inclusion criteria specified children between 9 and 17 years of age, children that have no cognitive impairment or other chronic illness, and children that have not begun orthodontic treatment. Exclusion criteria included the following: children that are above or below the specified age, children with cognitive impairment or other chronic illnesses, children with severe oral pain and limited range of motion of the jaws, children who are under psychological treatment, and children who have begun orthodontic treatment. Participants received a $20 financial incentive for participating and the response rate was 91 percent. Data were collected after gathering initial orthodontic clinical information as consistent with the IRB-approved protocol.
Participants completed the COHIP and clinical data were obtained from chart review. Spacing/crowding in millimeters of misalignment was assessed for each participant and included a simple measurement of overlap (crowding) or spacing between the six anterior maxillary and six anterior mandibular teeth. This measure is an adaptation of the irregularity index (
As part of a longitudinal study, the CF sample consisted of treatment-seeking children between the ages of 7 and 18 and their parent/caregiver. Trained research assistants at six established cleft treatment sites in the United States approached individuals scheduled for appointments who were identified, whenever possible, in advance as being in the correct age range for the study. Children were excluded if they were enrolled in a special class for mental disabilities, had a mental disorder, or did not read English or Spanish.
Youth assented and caregivers consented to a protocol approved by the IRBs at the respective sites. Participants had the choice of completing the COHIP in English or Spanish. Following uniform verbal instructions, participants independently completed the COHIP. Research assistants were available to provide assistance, if needed. Upon completion of the child and caregiver evaluation packets, a $25 gift card was dispensed to compensate for the participant's time and effort. These assessments are a part of our larger IRB-approved study.
Clinical data were collected by the clinical specialists and research assistants from the medical charts and/or clinical exams. These included whether a surgical recommendation in the next calendar year was recommended, visibility of defect [CLP versus cleft palate only (CPO)], ratings of patients’ hypernasality of speech, and the clinician's rating of extent of defect (a Likert-like scale from no difference or normal, mild, moderate to severe) is an adaptation of the severity scale developed by Kuijpers-Jagtman
The original COHIP consists of 34 items forming five conceptually distinct subscales: Oral Health, Functional Well-Being, Social-Emotional Well-Being, School Environment, and
Readability (appropriate US school grade level for language included in the questionnaire) was computed using the Flesch-Kincaid scoring protocol (
Additionally, test formatting to reduce fatigue and response error includes alternating line color, use of a clear font, and use of pictures for younger children. A cue sheet is also available for young children or those with limited attention or reading skills. The test instrument is completed in less than 10 minutes.
The development of the original 34-item COHIP has been detailed in previous publications (
Internal consistency was quantified using Cronbach's alpha. The acceptable level for the overall scale was set at 0.80. Also assessed was the ability of the reduced measure to differentiate between groups by clinical severity.
Analysis of variance was used to compare the three samples’ scores on the original COHIP and the COHIP-SF 19 (overall and subscales).
Two items captured oral health-related pain experience (had Two items assessed oral health-related challenges regarding oral hygiene (had Two items measured oral health-related eating challenges (had Two items included oral health-related challenges with speaking (had
The first three sets of items had similar distributional properties (normally distributed) and good range of endorsement coverage (all response options were used); additionally, change in alpha reliability upon deletion of either was negligible. The decision was made to retain the more general, less specific item (had pain) over the more specific item (pain or sensitivity . . . hot or cold things).In the case of the last pair of items with content overlap, we retained “difficulty saying certain words” as problems with speech intelligibility tend to subside with age (
A number of items on each subscale evidenced weak loadings (
The Oral Health item,
The mean [±standard deviation (SD)] age of the 205 children in this sample is 11.8 (±2.9) years. Just over half (55 percent) are male and 97 percent are Latino.
Internal consistency was assessed using Cronbach's alpha: COHIP Child = 0.87 compared with COHIP-SF 19 = 0.82.
COHIP-SF 19 scores were significantly lower for children with the greatest amount of DFS in permanent teeth on Oral Health [
COHIP-SF 19 scores were significantly lower for participants with caries in permanent teeth (compared with those with none) on Oral Health [
Parental ratings of the child's overall health were significantly positively correlated with scores on the COHIP-SF 19 as follows: Functional Well-Being (
The sample consists of 108 treatment-seeking youth. The participants averaged 12.7 years (SD = 2.0), and 50 percent were male. The sample was ethnically diverse: 21.7 percent black or African American, 55.6 percent Latino, 12.3 percent white, and 10.4 percent other (mostly Asian) (see
Internal consistency was assessed using Cronbach's alpha: COHIP Child = 0.86 and COHIP-SF 19 = 0.82.
Significant negative correlations revealed that higher clinical severity was associated with lower OHRQoL as measured by the COHIP-SF 19 for absolute levels of mandibular and maxilla crowding and spacing. This modified irregularity index revealed these correlations and significance scores for mandibular and maxilla anterior teeth: Oral Health (–0.37,
Findings using the COHIP were consistent with correlations for mandibular and maxilla irregularity: Oral Health (–0.40,
A total of 863 youth with CF anomalies participated (
Internal consistency of the COHIP-SF 19 was acceptable as assessed using Cronbach's alpha: child 0.88 and caregiver 0.87. These findings are consistent with the reliability of the original instrument that was also child 0.88 and caregiver 0.87.
Based on the clinical evaluation, children with greater defects had positive surgical recommendations compared with those who were clinically acceptable (no surgical recommendation). The results showed that COHIP-SF 19 scores were significantly lower among those children with less optimal clinical status (lower for those having surgical recommendations and higher for those children who had no surgical recommendation) on Functional Well-Being [
Given that most speech problems are resolved by adolescence (
Original COHIP scores followed a similar pattern for speech production: Oral Health [
Based on visibility of cleft defect, COHIP-SF 19 scores were significantly lower for those with CPO compared with those with CLP on Oral Health [
Extent of nose defect as measured by the plastic surgeon revealed that COHIP-SF 19 scores were significantly different (lower) for participants with more severe clinicians’ rating of extent of nose defect for Functional Well-Being [
Extent of lip defect as measured by the plastic surgeon revealed that COHIP-SF 19 scores were significantly different (lower) for participants with more severe clinicians’ rating of extent of lip defect for Functional Well-Being [
Convergent validity of the COHIP-SF 19 as assessed using patient's self-rated
The results from these three different samples indicate that the COHIP-SF 19 retains very good psychometric properties. Both reliability and validity testing are consistent with those reported in the literature for the original COHIP (
OHRQoL assessment in children seeks to measure items associated with the teeth, mouth, or face that are understood and meaningful to youth. The 3.2 grade readability level also makes the measure accessible to most school-aged children. Additionally, the ability of the measure to discriminate across clinical groups and within groups by extent of disease/defect highlights the shortened instrument's validity as well as its versatility compared with other children's OHRQoL measures.
One of the limitations of this report is that to date we do not have data on the responsiveness of the measure to change. It is noted that the instrument is currently being utilized as an evaluative measure for a longitudinal outcomes study and data on change following cleft surgery or no surgery will be reported. However, the COHIP, like many recent generic QoL tools,includes positive constructs which should reveal a more robust and responsive outcome measure (
The current findings support the position that subjective evaluation of oral health status provides unique data that correlate with clinical outcomes. In fact, the subjective assessment adds a dimension to the relative prevalence and/or importance of the individual or sample. Such data are invaluable when developing interventions and fully assessing the needs of the population. Such findings underscore why QoL measures are now incorporated into almost every area of healthcare and constitute a valuable oral health outcome measure (
Hillary L. Broder and Lacey Sischo are with the Cariology and Comprehensive Care, NYU. Maureen Wilson-Genderson is with the Department of Social and Behavioral Health, VCU School of Medicine.
Demographic Characteristics by Participant Group
| Pediatric ( | Orthodontic ( | Craniofacial ( | |
|---|---|---|---|
| Age [mean (SD)] | 11.8 (2.9) | 12.7 (2.0) | 11.9 (3.0) |
| Gender | |||
| Male (%) | 55 | 50 | 56 |
| Race/ethnicity (%) | |||
| Black | 0 | 22 | 10 |
| Asian | 0 | 6 | 10 |
| White | 0 | 12 | 68 |
| Other | 3 | 4 | 12 |
| Latino (%) | 97 | 56 | 14 |
Participants in the CF sample self-described as Latino/not Latino separately from selecting a race designation.
CF, craniofacial; SD, standard deviation.
Child Oral Health Impact Profile Original and Short Form
| Oral Health – Well-Being (original 10 items; five items retained) | Ped | Ortho | CF |
|---|---|---|---|
| Mean (SD) confirmatory factor analysis loadings | |||
| Had pain in your teeth/toothache | 3.0 (1.1) 0.66 | 3.0 (1.0) 0.12 | 3.0 (1.1) 0.57 |
| 2.9 (1.2) 0.09 | 2.8 (1.1) 0.16 | 2.1 (1.4) 0.47 | |
| Had discolored teeth or spots on your teeth | 3.3 (1.0) 0.43 | 3.1 (1.3) 0.44 | 3.2 (1.1) 0.46 |
| Had crooked teeth or spaces between your teeth | 2.6 (1.4) 0.44 | 2.7 (1.5) 0.27 | 1.6 (1.5) 0.08 |
| 3.1 (1.1) 0.09 | 3.4 (1.0) 0.07 | 2.9 (1.1) 0.55 | |
| Had bad breath | 2.7 (1.1) 0.56 | 2.7 (1.0) 0.56 | 2.6 (1.2) 0.52 |
| Had bleeding gums | 2.7 (1.1) 0.68 | 3.0 (1.1) 0.02 | 3.0 (1.1) 0.59 |
| 2.3 (1.1) 0.68 | 2.3 (1.1) 0.30 | 2.1 (1.2) 0.20 | |
| 2.5 (1.2) 0.55 | 2.5 (1.3) 0.29 | 2.6 (1.4) 0.45 | |
| 2.5 (1.1) 0.56 | 2.1 (1.1) 0.61 | 2.1 (1.2) 0.60 | |
| COHIP Oral Health Subscale (original 10 items) | 27.6 (6.5) | 26.5 (5.5) | 25.3 (6.6) |
| COHIP-SF 19 Oral Health Subscale (five items) | 13.8 (2.5) | 13.6 (2.9) | 13.4 (3.5) |
| Functional Well-Being (original six items; four items retained) | |||
| 3.2 (1.1) 0.59 | 3.4 (1.0) 0.33 | 2.8 (1.3) 0.64 | |
| Had difficulty eating foods you would like to eat | 3.3 (0.9) 0.69 | 3.4 (1.1) 0.35 | 3.1 (1.2) 0.73 |
| Had trouble sleeping | 3.6 (0.8) 0.66 | 3.0 (0.2) 0.43 | 3.6 (0.80) 0.56 |
| Had difficultly saying certain words | 3.4 (1.0) 0.70 | 3.3 (1.0) 0.44 | 2.7 (1.3) 0.68 |
| 3.4 (1.1) 0.69 | 3.4 (0.9) 0.34 | 2.7 (1.3) 0.52 | |
| Had difficulty keeping your teeth clean | 3.0 (1.2) 0.57 | 2.9 (0.7) 0.45 | 3.1 (1.1) 0.59 |
| COHIP Functional Well-Being Subscale (original six items) | 20.0 (3.8) | 19.3 (4.9) | 17.9 (4.0) |
| COHIP-SF 19 Functional Well-Being Subscale (four items) | 13.2 (2.6) | 12.5 (3.7) | 12.4 (2.09) |
| Social/Emotional Well-Being (original eight items; six items retained) | |||
| Been unhappy or sad | 3.0 (1.1) 0.55 | 2.9 (1.1) 0.73 | 3.0 (1.2) 0.78 |
| Felt worried or anxious | 3.1 (0.09) 0.69 | 3.0 (1.0) 0.77 | 3.1 (1.1) 0.75 |
| Avoided smiling or laughing with other children | 3.2 (0.08) 0.24 | 3.7 (1.1) 0.63 | 3.3 (1.2) 0.64 |
| Felt that you look different | 3.3 (1.1) 0.69 | 3.7 (1.2) 0.59 | 2.7 (1.3) 0.82 |
| Been worried about what other people think about your . . . | 3.0 (1.2) 0.65 | 3.4 (1.2) 0.08 | 2.7 (1.4) 0.79 |
| 3.0 (1.0) 0.71 | 2.3 (1.5) 0.84 | 3.1 (1.3) 0.63 | |
| Been teased, bullied, or called names by other children | 3.5 (1.1) 0.22 | 3.0 (1.0) 0.67 | 3.1 (1.4) 0.63 |
| 3.2 (0.09) 0.72 | 3.0 (1.3) 0.66 | 2.8 (1.2) 0.69 | |
| COHIP Emotional Well-Being Subscale (original eight items) | 25.3 (3.6) | 26.9 (4.4) | 24.9 (6.8) |
| School Environment (original four items; two retained) | |||
| Missed school for any reason | 3.5 (1.0) 0.55 | 3.2 (1.1) 0.25 | 2.9 (0.90) 0.51 |
| 3.5 (1.1) 0.58 | 3.0 (1.4) 0.07 | 3.5 (0.90) 0.37 | |
| Not wanted to speak/read out loud in class | 3.6 (1.0) 0.80 | 3.8 (0.5) 0.36 | 3.3 (1.0) 0.70 |
| 3.6 (1.1) 0.20 | 3.4 (1.1) 0.06 | 3.6 (0.90) 0.21 | |
| COHIP School Subscale (original four items) | 14.2 (2.3) | 13.5 (2.6) | 13.4 (2.8) |
| Self-Image (original six items; two retained) | |||
| Been confident | 1.8 (1.0) 0.35 | 1.8 (1.3) 0.10 | 2.1 (1.5) 0.48 |
| Felt that you were attractive (good looking) | 1.3 (1.3) 0.28 | 3.3 (1.1) 0.14 | 1.7 (1.4) 0.49 |
| 2.2 (1.2) 0.19 | 1.4 (1.0) 0.26 | 2.6 (1.3) 0.22 | |
| 2.9 (1.2) 0.12 | 2.5 (1.2) 0.08 | 3.3 (1.1) 0.47 | |
| 2.6 (1.3) 0.17 | 3.1 (0.0) 0.08 | 3.4 (0.90) 0.17 | |
| 2.7 (1.3) 0.10 | 2.7 (1.0) 0.11 | 3.6 (0.80) 0.62 | |
| COHIP Self-Image (original six items) | 13.5 (5.1) | 15.1 (4.7) | 16.7 (4.4) |
| COHIP-SF 19 Socio-Emotional Well-Being Subscale | 26.0 (5.0) | 28.7 (5.6) | 25.1 (6.9) |
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The retained items from the original Social/Emotional, School, and Self-Image domains are combined to create this subscale on the COHIP-SF 19.
Items not retained in Short Form.
Questions finish with “because of your teeth, mouth, or face.”
CF, craniofacial; COHIP-SF 19, Child Oral Health Impact Profile–Short Form 19; SD, standard deviation. Bolded items depict COHIP total scores.