Estimating the number of coronary artery bypass graft and percutaneous coronary intervention procedures in Canada: a comparison of cardiac registry and Canadian Institute for Health Information data sources.

BACKGROUND: Provincial cardiac registries and the Canadian Institute for Health Information (CIHI) pan-Canadian administrative databases are invaluable tools for understanding Canadian cardiovascular health and health care. Both sources are used to enumerate cardiovascular procedures performed in Canada. OBJECTIVE: To examine the level of agreement between provincial cardiac registry data and CIHI data regarding procedural counts for coronary artery bypass grafts (CABGs) and percutaneous coronary interventions (PCIs). METHODS: CIHI staff obtained CABG and PCI counts from seven provinces that, in 2004, performed these procedures and had a cardiac registry (ie, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Nova Scotia, and Newfoundland and Labrador). Structured mail questionnaires, and e-mail and telephone follow-ups elicited information from a designated registry respondent. The CIHI derived its counts of CABG and PCI procedures by applying the geographical boundaries, procedural definitions and analytical case criteria used by the cardiac registries to CIHI inpatient and day procedure databases. Steps were taken to reduce double-counting procedures when combining results from the two CIHI databases. Two measures were calculated: the absolute difference between registry and CIHI estimates, and the per cent agreement between estimates from the two sources. RESULTS: All seven cardiac registries identified as eligible for the study participated. Agreement was high between the two sources for CABG (98.8%). For PCI, the level of agreement was high (97.9%) when CIHI sources were supplemented with day procedure data from Alberta. CONCLUSIONS: The high level of agreement between cardiac registry and CIHI administrative data should increase confidence in estimates of CABG and PCI counts derived from these sources.

Oral health-related quality of life of children with oligodontia.

OBJECTIVES: To assess the functional and psychosocial impact of oligodontia in children aged 11-14 years. METHODS: Children aged 11-14 years with oligodontia were recruited from orthodontic clinics when they presented for orthodontic evaluation. All completed a copy of the Child Perceptions Questionnaire for 11- to 14-year olds, a measure of the functional and psychosocial impact of oral disorders. Information on the number and pattern of missing teeth for each child were obtained from charts and radiographs. RESULTS: Thirty-six children were included in the study. The number of missing teeth ranged from one to 14 (mean = 6.8). Just over three-quarters of the subjects reported experiencing one or more functional and psychosocial impacts 'Often' or 'Everyday/almost everyday'. Correlations between scale and sub-scale scores and the number of missing teeth were weak and nonsignificant. CONCLUSIONS: Children with oligodontia experience substantial functional and psychosocial impacts from the condition. When compared with other clinical groups, children with oligodontia appear to have worse oral health-related quality of life than children with dental decay and malocclusion, but better oral health-related quality of life than children with oro-facial conditions.

Day surgery visits for dental problems.

OBJECTIVES: To fill an information gap for dental care policy stakeholders in Canada, this pilot study explored the nature of day surgery (DS) visits for dental problems in Ontario, the country's largest province. METHODS: The Canadian Institute for Health Information's National Ambulatory Care Reporting System was used, which contains demographic, diagnostic, procedural and administrative information for ambulatory care settings across Ontario. Fiscal years 2003/2004 to 2005/2006 data were included for DS visits that had a main problem coded with an International Classification of Diseases code in the range K00-K14, representing diseases of the oral cavity, salivary glands and jaws. RESULTS: During this period, approximately 75 791 persons made 79 133 DS visits for dental problems in Ontario. Proportionally, children under 5 years of age with dental caries represent the majority of DS visits. Restorations and extractions were the most frequently performed DS care procedure. CONCLUSIONS: This is the first study of its kind in Canada, and confirms many of the assumptions held about DS care for dental problems. The study also acts as a baseline for ongoing quality improvement and planning within the province of Ontario.

Emergency department visits for dental care of nontraumatic origin.

OBJECTIVES: To explore the nature of emergency department (ED) visits for dental problems of nontraumatic origin in Canada's largest province, Ontario. METHODS: The Canadian Institute for Health Information's National Ambulatory Care Reporting System was used, which contains demographic, diagnostic, procedural and administrative information from hospital-based ambulatory care settings across Ontario. Data of fiscal years 2003/04 to 2005/06 were included for emergency visits that had a main problem coded with an International Classification of Diseases - 10th edition code in the range K00-K14, representing diseases of the oral cavity, salivary glands and jaws. Volumes are presented by a number of different factors in order to describe patient and visit characteristics. RESULTS: During this period, there were a total of 141 365 ED visits for dental problems of nontraumatic origin in Ontario, representing an estimated 116 357 persons. Approximately half of all visits (54%) were made by those 20 to 44 years old, and associated with periapical abscesses and toothaches (56%). The great majority (78%) were triaged as nonurgent, and most (93%) were discharged home. CONCLUSION: ED visits for dental problems of nontraumatic origin are not insignificant. Over the study period, these visits were greater than for diabetes and hypertensive diseases. Policy efforts are needed to provide alternative options for seeking emergency dental care in Ontario.

Direction of wording and responses to items in oral health-related quality of life questionnaires for children and their parents.

OBJECTIVES: In order to minimize acquiescence response set bias, it is often recommended that questionnaires measuring attitudes, behaviours or health states contain items worded positively and negatively. It has also been suggested that when measuring health status this approach means that both the negative and positive dimensions of health can be assessed. This study aimed at assessing the performance of negatively and positively worded items in questionnaires to measure child and parent perceptions of child oral health-related quality of life. METHODS: Both the child and parent questionnaire included four pairs of items, one negatively worded and one positively worded, that assessed eating, appearance, oral self-care and self-confidence. The response format was a five-point Likert frequency scale with a 'Don't know' option. Prior to analysis, the positive items were reverse coded. The relative performance of the two sets of items was assessed by means of comparisons of the proportions with 'Don't know' responses or missing values, mean item scores and proportions with the two highest frequency codes. Kappa statistics and intraclass correlation coefficients were used to assess the agreement between the negative and reverse-coded positive items and scores and the agreement between child and parent pairs. Factor analysis was used to determine if the two sets of items were measuring the same underlying construct. RESULTS: The study was completed by 91 Canadian children and 100 parents (91 child-parent pairs) recruited from clinics treating paediatric, orthodontic and oro-facial conditions. The positively worded items elicited substantially more 'Don't know' responses or missing values than the negatively worded items and failed to discriminate between groups. In addition, mean item scores and proportions with the highest frequency codes were substantially larger for reverse-coded positive than negative items. Agreement between pairs of items was slight. Child-parent agreement was substantial for a scale constructed from the negative items but only moderate for the positive items. Factor analysis revealed that the two sets of items loaded onto different factors. CONCLUSIONS: The performance of the positively worded items was unsatisfactory and their use in oral health-related quality of life indexes, either to reduce response set or assess positive oral health, is at best questionable.

Is the Child Perceptions Questionnaire for 11-14 year olds sensitive to clinical and self-perceived variations in orthodontic status?

OBJECTIVES: To assess the association between scores on the Child Perceptions Questionnaire for 11-14 year olds (CPQ11-14) and clinical and self-perceived measures of malocclusion. METHODS: Children were recruited from an orthodontic clinic just prior to starting orthodontic treatment. They completed a copy of the CPQ11-14 and a short questionnaire concerning their feelings about the condition of their teeth. Study models were taken and rated according to the Dental Aesthetic Index (DAI) and the Peer Assessment Rating (PAR) index by two sets of three examiners. Intra and inter-rater reliabilities for the two sets of examiners ranged from 0.80 to 0.99. CPQ11-14 scores were calculated for the full 35-item version and for 16 and 8-item short forms by summing the item response codes. The association between these scores, the DAI and PAR ratings and self-perceived measures of malocclusion were examined using appropriate parametric and nonparametric tests. RESULTS: Complete data were collected for 141 children, 63 boys and 78 girls. The mean age was 12.5 (SD = 1.0). DAI scores ranged from 17.0 to 58.0 with a mean of 35.0 (SD = 8.0). The distribution of subjects across the four severity categories was minor/none - 6.6%, definite - 35.2%, severe - 15.6% and handicapping 42.6%. PAR scores ranged from 8.0 to 66.0 with a mean of 31.4 (SD = 11.1). Eight percent had scores of 50 or above indicating marked deviation from an ideal occlusion. Both the long and the short forms of the CPQ11-14 identified substantial variability in the impacts of malocclusion. Correlations between CPQ11-14 scores and the orthodontic indices ranged from 0.26 to 0.31 (P < 0.01). There was a clear gradient in CPQ11-14 scores across four categories of the PAR based on quartiles. The gradient across the DAI categories was less clear. There were significant associations between all CPQ11-14 scores and the children's self-ratings of oral health, ratings of the extent to which the condition of the teeth affected life overall and expressions of happiness with the appearance and arrangement of the teeth. CONCLUSION: The results provide some evidence of the validity of the CPQ11-14 when used with children needing orthodontic treatment. However, because clinical samples are biased the study needs to be repeated in different treatment settings in order to confirm the utility of the measure.

Does self-weighting of items enhance the performance of an oral health-related quality of life questionnaire?

OBJECTIVES: To determine if self-weighting of the items in an oral health-related quality of life questionnaire improves its psychometric properties. METHODS: The Surgical Orthodontic Outcome Questionnaire (SOOQ) was designed to assess the oral health-related quality of life of individuals before and after corrective surgery. Each of its 33 'items' consists of two questions: a question concerning the frequency with which a given functional or psychosocial problem had been experienced and a 'weighting' question which asked about how much the individual was bothered by that problem. The questionnaire was completed by three groups of individuals: (i) pretreatment; (ii) immediate (i.e. 2-6 months) postsurgery and (iii) postsurgery (i.e. more than 2 years after surgery). Unweighted scale scores were obtained by summing the response codes to the frequency question and weighted scores by summing the products of the frequency and bother questions. These scores were calculated for the full questionnaire and a short form consisting of 15 items. The discriminative and correlational construct validity of these scores was compared along with internal consistency reliability. The sensitivity to change and longitudinal construct validity of unweighted and weighted scores was assessed in a simulated evaluative study in which pretreatment and postsurgery subjects were paired. RESULTS: For both the long and short forms of the questionnaire, unweighted and weighted scores discriminated between the groups enrolled in the study. Correlations with a general health rating were similar, as were Cronbach's alpha values and test-retest reliabilities. The simulated evaluative study suggested no differences in sensitivity to change or longitudinal construct validity. When subscale scores were examined, there was a suggestion that weighting improved their reliability. CONCLUSIONS: Self-weighting of items did not substantially improve the performance of the SOOQ. Domain weights should be developed and tested to determine if they have an effect on its properties.

Short forms of the Child Perceptions Questionnaire for 11-14-year-old children (CPQ11-14): development and initial evaluation.

BACKGROUND: The Child Perceptions Questionnaire for children aged 11 to 14 years (CPQ11-14) is a 37-item measure of oral-health-related quality of life (OHRQoL) encompassing four domains: oral symptoms, functional limitations, emotional and social well-being. To facilitate its use in clinical settings and population-based health surveys, it was shortened to 16 and 8 items. Item impact and stepwise regression methods were used to produce each version. This paper describes the developmental process, compares the discriminative properties of the resulting four short-forms and evaluates their precision relative to the original CPQ11-14. METHODS: The item impact method used data from the CPQ11-14 item reduction study to select the questions with the highest impact scores in each domain. The regression method, where the dependent variable was the overall CPQ11-14 score and the independent variables its individual questions, was applied to the data collected in the validity study for the CPQ11-14. The measurement properties (i.e. criterion validity, construct validity, internal consistency reliability and test-retest reliability) of all 4 short-forms were evaluated using the data from the validity and reliability studies for the CPQ11-14. RESULTS: All short forms detected substantial variability in children's OHRQoL. The mean scores on the two 16-item questionnaires were almost identical, while on the two 8-item questionnaires they differed by only one score point. The mean scores standardized to 0-100 were higher on the short forms than the original CPQ11-14 (p < 0.001). There were strong significant correlations between all short-form scores and CPQ11-14 scores (0.87-0.98; p < 0.001). Hypotheses concerning construct validity were confirmed: the short-forms' scores were highest in the oro-facial, lower in the orthodontic and lowest in the paediatric dentistry group; all short-form questionnaires were positively correlated with the ratings of oral health and overall well-being, with the correlation coefficient being higher for the latter. The relative validity coefficients were 0.85 to 1.18. Cronbach's alpha and intraclass correlation coefficients ranged 0.71-0.83 and 0.71-0.77, respectively. CONCLUSION: All short forms demonstrated excellent criterion validity and good construct validity. The reliability coefficients exceeded standards for group-level comparisons. However, these are preliminary findings based on the convenience sampling and further testing in replicated studies involving clinical and general samples of children in various settings is necessary to establish measurement sensitivity and discriminative properties of these questionnaires.

Bariatric surgery in Canada: obesity rates for Canadian adults are much higher today than in the past; however, rates of bariatric surgery, a treatment for high-risk severely obese individuals, have not risen in parallel.

Obesity rates for Canadian adults are much higher today than in the past, raising questions about how to achieve healthy weights and mitigate the associated health risks. While not a solution at the population level, bariatric surgery may be a treatment option for a relatively small proportion of obese individuals. In Canada, unlike in the United States, no consistent trend was evident in the use of this surgery between 1996-97 and 2003-04 across the five provinces for which comparable data were available. In 2003-04, bariatric surgeries were performed predominantly for women (87%); the average length of stay in hospital was 5 days; and 1.4% of patients were readmitted to hospital within 7 days of their discharge after surgery.

Missed opportunity: patients who leave emergency departments without being seen.

The rate of patients who visit emergency departments (EDs) but leave before being evaluated and treated is an important indicator of ED performance. This study examines patient- and hospital-level characteristics that may increase the risk of patients leaving EDs before being seen. The data are from the National Ambulatory Care Reporting System, an administrative database, and represent 4.3 million patient visits made to 163 Ontario EDs between April 2003 and March 2004. Among these data, the proportion that left without being seen (LWBS) was 3.1% (136,805). The rate of LWBS was highest among patients aged 15 to 35 years, those with less acute conditions and facilities that handle the highest volume of patients. Facility rates were positively correlated with facility median ED length of stay, annual facility volume and percentage of inpatient admissions. Understanding patient and facility characteristics that increase rates of LWBS may inform the process of developing measures to ensure timely access to ED care for all who seek it.

What do older adults' global self-ratings of oral health measure?

OBJECTIVE: Although global self-ratings of oral health are widely used in oral health research, the frames of reference on which older people's ratings are based are not known. This study used a quantitative approach in order to identify these referents. METHODS: Data were collected from 498 dentate subjects aged 53 years and over who took part in the second stage of a three-phase longitudinal epidemiological and sociodental study. Data were obtained by means of a personal interview and clinical oral examination and a self-complete version of the 49-item Oral Health Impact Profile (OHIP). These data were used to construct measures of oral disorders, oral symptoms, the functional and psychosocial impacts of oral disorders, health behaviours and contextual variables such as general health status, socioeconomic status and sociodemographic characteristics. Bivariate and linear regression analyses were used to identify which of these variables predicted self-ratings of oral health. RESULTS: One quarter of subjects stated that their oral health was only fair or poor. At the bivariate level most variables were associated with self-ratings of oral health. The regression model for all subjects indicated that the most important predictor of these self-ratings was the OHIP functional limitations sub-scale score. This explained 23% of the variation in the self-ratings. Six other variables entered the model and increased the R2 value to 0.36. There was some variation in the models and the influence of various factors by age and educational attainment. CONCLUSIONS: The results suggest that the referents that inform older adults' ratings of oral health are broadly similar to those that have been reported to inform their ratings of general health and differ across groups.

Health-related quality of life of children aged 11 to 14 years with orofacial conditions.

OBJECTIVE: To assess the health-related quality of life (HRQoL) of 11- to 14-year-old children with orofacial conditions. DESIGN: Thirty-nine patients with orofacial conditions were compared with 32 patients with dental caries. OUTCOME MEASURE: The multidimensional 37-item Child Perceptions Questionnaire for 11- to 14-year-old children (CPQ(11-14)). This forms one component of the Child Oral Health Quality of Life Questionnaire. RESULTS: The orofacial group had slightly higher scores on the CPQ(11-14) than the dental group (p < .05). The scores were slightly to moderately higher on the functional limitations (p < .01) and social well-being (p < .01) domains. The groups did not differ with respect to oral symptoms or emotional well-being. Mouth breathing, problems with speech, missing school, being teased, and being asked questions about their condition were the only issues reported more frequently by the orofacial group (p < .01). There was no evidence of social inhibition or withdrawal in the orofacial group. The children with orofacial conditions rated their oral health better than the children with dental decay (p < .05). In both groups, the majority of children reported that their condition had little impact on their life overall. CONCLUSIONS: Based on CPQ(11-14) scores, there were few differences in the HRQoL of 11- to 14-year-old children with orofacial conditions, compared with children with dental caries. This suggests that the majority of these children are well adjusted and able to cope with the adversities they experience as a result of their conditions. This may reflect the quality of the team approach used at the treatment setting at which they were recruited.

What do children's global ratings of oral health and well-being measure?

OBJECTIVES: To explore the constructs children incorporate in the responses to global ratings of their oral health (OH) and OH-related overall well-being (OWB). METHODS: Data were collected as part of a project to validate the Child Perceptions Questionnaire for ages 11-14 (CPQ11-14), a self-report measure of OH-related quality of life. Its 37 questions are organized in the symptoms, functional limitations, emotional and social well-being domains. Children were recruited from paediatric dentistry, orthodontic and orofacial dental clinics. To identify the CPQ11-14 domain scores and questions predicting the global ratings, correlation and multiple regression analyses were used. RESULTS: Of the 123 children, 22.8% rated their OH as 'Fair/Poor' and 30.1% reported that their OWB was affected by their oral/orofacial condition. Positive significant correlations were observed between the OH ratings and the CPQ11-14 oral symptoms and emotional well-being domains, and between the OWB ratings and all four CPQ11-14 domains. The number of the CPQ11-14 questions significantly correlated with the OH and OWB ratings were 8 and 19, respectively. Only the symptoms domain entered the model for the OH (R2=0.05), while age, functional limitations and emotional well-being domains predicted the OWB (R2=0.18). The OH model included three questions (R2=0.13) and the OWB model included age and six questions (R2=0.25). In both models all but one of the questions came from the emotional and social well-being domains. CONCLUSIONS: These findings suggest that children view OH and its impact on well-being as multidimensional concepts. Further research, including qualitative studies, is needed to better understand the referents children use when responding to global ratings and the factors that determine their responses.

Assessing the responsiveness of measures of oral health-related quality of life.

OBJECTIVES: This paper illustrates ways of assessing the responsiveness of measures of oral health-related quality of life (OHRQoL) by examining the sensitivity of the oral health impact profile (OHIP)-14 to change when used to evaluate a dental care program for the elderly. METHODS: One hundred and sixteen elderly patients attending four municipally funded dental clinics completed a copy of the OHIP-14 prior to treatment and 1 month after the completion of treatment. The post-treatment questionnaire also included a global transition judgement that assessed subjects' perceptions of change in their oral health following treatment at the clinics. Change scores were calculated by subtracting post-treatment OHIP-14 scores from pre-treatment scores. The longitudinal construct validity of these change scores were assessed by means of their association with the global transition judgements. Measures of responsiveness included effect sizes for the change scores, the minimal important difference, and Guyatt's responsiveness index. An receiver operating characteristic (ROC) curve was constructed to determine the accuracy of the change scores in predicting whether patients had improved or not as a result of the treatment. RESULTS: Based on the global transition judgements, 60.2% of subjects reported improved oral health, 33.6% reported no change, and only 6.2% reported that it was a little worse. These changes are reflected in mean pre- and post-treatment OHIP-14 scores that declined from 15.8 to 11.5 (P < 0.001). Mean change scores showed a consistent gradient in the expected direction across categories of the global transition judgement, but differences between the groups were not significant. However, paired t-tests showed no significant differences in the pre- and post-treatment scores of stable subjects, but showed significant declines for subjects who reported improvement. Analysis of data from stable subjects indicated that OHIP-14 had excellent test-retest reliability with an intraclass correlation coefficient (ICC) of 0.84. Effect size based on change scores for all subjects and subgroups of subjects were small to moderate. The ROC analysis indicated that OHIP-14 change scores were not good "diagnostic tests" of improvement. The minimal important difference for the OHIP-14 was of 5-scale points, but detecting this difference would require relatively large sample sizes. CONCLUSIONS: OHIP-14 appeared to be responsive to change. However, the magnitude of change that it detected in the context described here was modest, probably because it was designed primarily as a discriminative measure. The psychometric properties of the global transition judgements that often provide the "gold standard" for responsiveness studies need to be established.

Questionnaire for measuring oral health-related quality of life in eight- to ten-year-old children.

PURPOSE: This study measured oral health-related quality of life for children, which involved the construction of child perceptions questionnaires (CPQs) for ages 6 to 7, 8 to 10, and 11 to 14. The purpose of this study was to present the development and evaluation of the CPQ for 8- to 10-year-olds (CPQ8-10). METHODS: Questions (N=25) were selected from the CPQ for 11- to 14-year-olds based on the child development literature and input from parents, child psychologist, and teacher of grades 3 and 4. Validity and reliability were evaluated on 68 and 33 children, respectively. RESULTS: There was a positive moderate correlation between the CPQ8-10 score and overall well-being rating (R=.45). The level of impact was slightly higher in the orofacial than in the pediatric dentistry group (mean score=19.1 vs 18.4, respectively). Hypotheses concerning the relationship between the CPQ8-10 score and number of decayed surfaces were confirmed with R=.29, and the mean score higher in caries-afflicted than caries-free children (21.1 vs 14.7). The Cronbach's alpha and intraclass correlation coefficients were 0.89 and 0.75, respectively. CONCLUSIONS: Results suggest good construct validity, internal consistency, reliability and test-retest reliability, but do not demonstrate discriminative validity. This is consistent, however, with theoretical models of oral disease and its consequences. Further research is required, as these are preliminary findings based on convenience sampling.

Agreement between mothers and children aged 11-14 years in rating child oral health-related quality of life.

OBJECTIVES: To assess the agreement between mothers and children concerning the child's oral health-related quality of life. METHODS: A total of 42 pairs of mothers and children aged 11-14 years with oral and orofacial conditions completed the parental (PPQ) and child (CPQ(11-4)) components of the Child Oral Health Quality of Life Questionnaire. The PPQ and CPQ(11-14) are analogous questionnaires with 31 common items. Agreement between overall and subscale scores derived from the questionnaires were assessed in comparison and in correlation analyses. The former used mean directional differences between mothers and children to assess bias and mean absolute differences to assess agreement at the group level. The latter used intraclass correlation coefficients (ICCs) to assess agreement at the level of individual mother-child pairs. RESULTS: At the group level, agreement between mothers and children was good. There was little evidence of bias in mothers' reports compared to those of their children. The mean absolute difference in overall scores constituted 9% of the possible range of scores. However, the significance of this difference is difficult to interpret. The ICC for overall scores was 0.70 indicating substantial agreement between mother and child pairs. However, the ICCs for the emotional and social well-being subscales indicated moderate agreement only. There was a suggestion that the level of agreement varied according to the characteristics of the child. CONCLUSION: Although mothers may be used as proxies for their children in some circumstances and for some purposes, the views of both should be obtained in order to fully represent child oral health-related quality of life.

Measuring parental perceptions of child oral health-related quality of life.

OBJECTIVES: The aim of this study was to develop and evaluate the P-CPQ, a measure of parental/caregiver perceptions of the oral health-related quality of life of children. This forms one component of the Child Oral Health Quality of Life Questionnaire (COHQOL). METHODS: An item pool was developed through a review of existing child health questionnaires and interviews with parents/caregivers of children with pedodontic, orthodontic, and orofacial conditions. The resulting 47 items were used in a study in which 208 parents/caregivers provided data on their frequency and importance. The 31 items rated the most frequent and important were selected for the final questionnaire (P-CPQ). The P-CPQ validity and reliability were assessed by a new sample of 231 parents, 79 of whom completed two copies for the assessment of test-retest reliability. RESULTS: The P-CPQ discriminated among the three clinical groups included in the expected direction. Within-group analyses using clinical data provided some evidence that scores were associated with the severity of the condition. The P-CPQ also showed good construct validity. It had excellent internal consistency reliability with a Cronbach's alpha of 0.94 and demonstrated perfect test-retest reliability (ICC=0.85). CONCLUSION: The study provides data to indicate that the P-CPQ is valid and reliable.

Family impact of child oral and oro-facial conditions.

OBJECTIVES: The aim of this study was to develop and evaluate the Family Impact Scale, a measure of the family impact of child oral and oro-facial disorders. This formed one component of the Child Oral Health Quality of Life Instrument. METHODS: The scale was developed using a process described by Guyatt et al. (1987) and Juniper et al. (1996). An item pool was developed using a review of existing child health status and family impact questionnaires, interviews with 41 parents-caregivers of children with paedodontic, orthodontic and oro-facial conditions and discussions with dental specialists. The resulting pool of 21 items was used in an item impact study in which 93 parents-caregivers provided data on the frequency and importance of these items. The 14 items identified most frequently or rated the most important were selected for the final questionnaire. The discriminant and construct validity and internal consistency reliability of this 14-item scale were assessed in a study of 266 parents-caregivers from the three clinical groups. Seventy-nine of these participants completed a second copy of the questionnaire to facilitate assessment of test-retest reliability. RESULTS: Family Impact Scale scores ranged from 0 to 33, indicating that the measure was sensitive to variations in family impact. Floor effects were minimal with only 10.2% of subjects having a score of zero and there were no ceiling effects, that is, subjects with maximum scores. Almost three-quarters of parents-caregivers reported some family impact 'sometimes' or 'often/everyday' over the previous 3 months. Impact on parental or family activities of this frequency was reported by 53.0%, impact on parental emotions by 44.0%, conflict in the family by 31.6% and financial difficulties by 31.2%. The measure and its component items were reasonably good at discriminating between the three clinical groups included in the study and showed good construct validity. It had excellent internal consistency reliability with a Cronbach's alpha of 0.83 and was reproducible for parent-caregivers who reported that their child's condition was stable (ICC = 0.80). CONCLUSIONS: The study provides some data to suggest that child oral and oro-facial conditions have a pervasive impact on the family. The Family Impact Scale had good technical properties. Its evaluative properties need to be tested in longitudinal studies.