Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Questionnaires”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources
PubMed2006

Validation of a water consumption questionnaire for a study of the adverse health outcomes associated with disinfection by-products.

The aim of this study was to assess the validity and reliability of a questionnaire to estimate water exposure through drinking, showering, bathing or swimming. Forty-seven pregnant women were recruited from antenatal or exercise classes and were randomly allocated into three groups. The first group completed the water exposure questionnaire one-week apart. The second group completed a three-day diary and then the questionnaire. The third group completed the questionnaire first followed by the diary. Agreement was assessed by the Intraclass correlation coefficient (ICC) and the Kappa statistic. The questionnaire demonstrated good reliability (ICC 0.93 for water consumption and 0.91 for time spent showering). With regard to validity, average daily water consumption was estimated to be 8.1 glasses/day (2 litres) from the diary compared with 12.2 (3 litres) from the questionnaire. The ICCs comparing the diary and questionnaire responses were 0.31 for water consumption and 0.72 for showering. The water exposure questionnaire overestimated levels of exposure when compared with diary-reporting of consumption. While a water exposure questionnaire may be a less intrusive research instrument than a diary, further development is required to improve the validity of this instrument.

Adult↗
PubMed2006

The new Swedish Post-Concussion Symptoms questionnaire: a measure of symptoms after mild traumatic brain injury and its concurrent validity and inter-rater reliability.

OBJECTIVE: To study the concurrent validity and the inter-rater reliability of the Post-Concussion Symptoms Questionnaire. DESIGN: The approach was to study the concurrent validity of the Post-Concussion Symptoms Questionnaire when used as an interview questionnaire compared with a self-report questionnaire administered by the patients. The inter-rater reliability was also studied when 2 different raters administered the Post-Concussion Symptoms Questionnaire interview. PATIENTS: Thirty-five patients with mild traumatic brain injury were consecutively contacted by telephone and asked whether they would be willing to participate in a follow-up intervention. METHODS: The Post-Concussion Symptoms Questionnaire was completed by the patients, who answered "Yes" or "No" to the standardized questions. The patients were then interviewed to check the certain "Yes" or "No" answers, 0-10 days after having completed the first Post-Concussion Symptoms Questionnaire. The raters filled in their ratings independently. RESULTS: The concurrent validity of answers in the questionnaire compared with those in the interview ranged from 82% to 100% agreement. The inter-rater reliability results ranged from 93% to 100% agreement between the raters. CONCLUSION: The Post-Concussion Symptoms Questionnaire with answers of "Yes" or "No" is a valid instrument. High reliability was found between the raters.

Adolescent↗
PubMed1997

Assessments of food-frequency questionnaires in minority populations.

To assess the performance of food-frequency questionnaires in minority populations, we reviewed published studies of such questionnaires with respect to reports of reliability, bias in mean intake estimates, validity, and factors that might affect these characteristics, including the method by which a questionnaire was developed. Because of the small number of studies and the variation in their methods, the results of the review are not easily summarized and cannot be generalized. Most reliability correlation coefficients were in the range usually reported in evaluations of the performance of questionnaires in nonminority populations (0.5-0.8). Mean intakes derived from questionnaires were generally higher than those estimated with use of referent methods, although this varied according to the population, questionnaire, and nutrient being assessed; moreover, the accuracy of the referent method was questioned by some investigators. Validation correlation coefficients were variable, with some indicating that the questionnaires performed less well in certain populations. Additional research is needed on the performance of food-frequency questionnaires in minority and multicultural populations and on determining how best to develop such questionnaires.

Black or African American↗
PubMed2004

Comparability of skin screening histories obtained by telephone interviews and mailed questionnaires: a randomized crossover study.

The comparability of information collected through telephone interviews and information collected through mailed questionnaires has not been well studied. As part of the first phase of a randomized controlled trial of population screening for melanoma in Queensland, Australia, the authors compared histories of skin examination reported in telephone interviews and self-administered mailed questionnaires. A total of 1,270 subjects each completed a telephone interview and a mailed questionnaire 1 month apart in 1999; 564 subjects received the interview first, and 706 received the mailed questionnaire first. Agreement between the two methods was 91.2% and 88.6% for whole-body skin examination by a physician in the last 12 months and the last 3 years, respectively, and 81.9% for whole-body skin self-examination in the last 12 months. Agreement was lower for "any" skin self-examination. Agreement between the two methods was similar regardless of whether the interview or the questionnaire was administered first. Missing data were less frequent for interviews (0.5%) than for mailed questionnaires (3.8%). Costs were estimated at A$9.55 (US$6.21) per completed interview and A$3.01 (US$1.96) per questionnaire. The similarity of results obtained using telephone interviews and mailed questionnaires, coupled with the substantially higher cost of telephone interviews, suggests that self-administered mailed questionnaires are an appropriate method of assessing this health behavior.

Adult↗
PubMed1993

Hearing conservation in the mining industry. Evaluation of a risk factor questionnaire.

The objectives of this study were to assess the validity of a self-administered hearing questionnaire in the assessment of risk to hearing, to amend the questionnaire design as necessary, and to give general guidance on the use of audiometric questionnaires in hearing conservation programmes. The study was carried out at a colliery in Staffordshire. The odds of deafness, according to the Health and Safety Executive definition, were analysed by exposure to the hearing risk variables in the questionnaire. The results of the hearing questionnaire were linked to a cross-sectional audiometric survey. There were 189 questionnaires eligible for inclusion. Noise exposure at work was reasonably well predicted by having to shout at work (OR 1.42, 95 per cent CI 0.58-3.54) and being exposed to noisy tools and machinery (OR 2.12, 95 percent CI 0.72-6.72). Risk to hearing from disease was predicted by having 'abnormal' hearing or discharging ears, but not by any of the other exposure variables. Risk to hearing from acoustic trauma was demonstrated for fire-arms (OR 1.23, 95 per cent CI 0.5-2.98). None of the hobbies included in the questionnaire usefully predicted hearing loss. The conclusions are that, contrary to Health and Safety Executive advice, audiometric questionnaires may reasonably be administered to all employees, as they are useful in the documentation of hearing loss risk factors. They should not, however, be used to detect ear disease. A revised questionnaire was drafted as the result of these findings, and will be piloted in a larger population.

Evaluation Studies as Topic↗
PubMed1997

Screening questionnaires for bakers' asthma--are they worth the effort?

The use of a respiratory screening questionnaire is recommended annually to screen bakery workers in the UK. We compared questionnaire screening with other methods of detecting workers with asthmatic symptoms and then assessed the significance of these symptoms with careful investigation and follow-up. Reasons for questionnaire failures were then explored. A questionnaire was issued to 362 flour-exposed workers in a large bakery. All positive respondents to respiratory symptom questions were interviewed by an occupational nurse. Workers with occupationally related symptoms at this interview were referred to the chest clinic. In addition, workers with negative questionnaires were screened using attendance records, sick notes and direct workplace observations. Workers with frequent absence from work or sick notes with respiratory diagnoses were interviewed in the same manner as those answering the questionnaire positively and then referred to clinic. At clinic, a diagnosis was made for each worker on the basis of clinical assessment, spirometry, serial peak expiratory flow rate (PEFR) analysis and radioallergosorbent testing (RAST) testing for specific IgE. Using the clinic diagnoses, the referral routes were audited to assess the rates of case detection of asthma and occupational asthma. The respiratory screening questionnaire identified 68 workers with respiratory symptoms. Of these, 21 proceeded to full assessment. A diagnosis of asthma was made in five cases, one of which was bakers' asthma. In addition, 11 workers not reporting any symptoms by questionnaire were referred to clinic and five were diagnosed as having asthma. Screening questionnaires may lead to an underestimate of the prevalence of asthmatic symptoms and as such should not be used alone in workplace screening.

Adult↗
PubMed1985

Reproducibility and validity of a semiquantitative food frequency questionnaire.

The aim of this study was to evaluate the reproducibility and validity of a 61-item semiquantitative food frequency questionnaire used in a large prospective study among women. This form was administered twice to 173 participants at an interval of approximately one year (1980-1981), and four one-week diet records for each subject were collected during that period. Intraclass correlation coefficients for nutrient intakes estimated by the one-week diet records (range = 0.41 for total vitamin A without supplements to 0.79 for vitamin B6 with supplements) were similar to those computed from the questionnaire (range = 0.49 for total vitamin A without supplements to 0.71 for sucrose), indicating that these methods were generally comparable with respect to reproducibility. With the exception of sucrose and total carbohydrate, nutrient intakes from the diet records tended to correlate more strongly with those computed from the questionnaire after adjustment for total caloric intake. Correlation coefficients between the mean calorie-adjusted intakes from the four one-week diet records and those from the questionnaire completed after the diet records ranged from 0.36 for vitamin A without supplements to 0.75 for vitamin C with supplements. Overall, 48% of subjects in the lowest quintile of calorie-adjusted intake computed from the diet records were also in the lowest questionnaire quintile, and 74% were in the lowest one of two questionnaire quintiles. Similarly, 49% of those in the highest diet record quintile were also in the highest questionnaire quintile, and 77% were in the highest one or two questionnaire quintiles. These data indicate that a simple self-administered dietary questionnaire can provide useful information about individual nutrient intakes over a one-year period.

Adult↗
PubMed1988

Reproducibility and validity of dietary assessment instruments. II. A qualitative food frequency questionnaire.

The reproducibility and validity of a food frequency questionnaire designed to measure intakes of total fat, saturated and polyunsaturated fats, vitamins A, C, and E, selenium, and dietary fiber were tested from March to October 1984 among 297 Finnish men aged 55-69 years. The questionnaire asked about consumption of 44 food items. In the reproducibility study, 107 subjects filled in the questionnaire three times, at three-month intervals. Intraclass correlations varied from 0.52 for vitamin A to 0.85 for polyunsaturated fat. In the validity study, 190 subjects kept food consumption records for 12 two-day periods distributed evenly over a period of six months and filled in the questionnaire both before and after this period. Correlations between the nutrient intake values from the food records and those from the food frequency questionnaires ranged from 0.33 for selenium to 0.68 for polyunsaturated fat. On the average, 40-45% of the subjects in the lowest and highest quintiles based on food records were in the same respective quintiles when assessed by the food frequency questionnaire, and 70-75% were in the two lowest and two highest questionnaire quintiles, respectively. The food frequency questionnaire and a quantitative food use questionnaire tested in the same study were compared. Use of these two instruments in large-scale epidemiologic studies is discussed.

Ascorbic Acid↗
PubMed1990

Validation and comparison of eight physical activity questionnaires.

Several questionnaires are available for assessing physical activity, but few of these instruments have been validated, particularly with respect to energy balance. Twenty-one healthy men 28-55 years old participating in a free-living, controlled feeding experiment completed eight widely used physical activity questionnaires. These were compared with measured caloric intake and resting energy expenditure during a period of stable body weight. Physical activity indices or daily energy expenditure estimates derived from the questionnaires generally increased with energy intake. The questionnaires were moderately well correlated with each other; interquestionnaire correlation coefficients ranged from 0.09 to 0.81 (median = 0.53). Correlations between the questionnaires and energy intake, which ranged from 0.13 for the Minnesota Leisure Time Activity instrument to 0.49 for the Harvard Alumni questionnaire, were higher than between the questionnaires and nonresting energy expenditure; that is, energy intake minus resting energy expenditure (correlation coefficient range 0.05-0.32). The Five-City Project questionnaire yielded an average estimate of total caloric expenditure that most closely approximated intake (96%). These data indicate that although estimates of individual energy expenditure or physical activity may be less than optimal, most of the questionnaires evaluated provide reasonable group means for these parameters.

Adult↗
PubMed1998

Performance of a self-administered mailed version of the Quality of Well-Being (QWB-SA) questionnaire among older adults.

OBJECTIVES: The Quality of Well-Being questionnaire is a measure of health-related quality of life (HRQoL) that has several desirable properties. Its widespread use has been hindered because it is difficult to administer. To overcome this limitation, a new self-administered form has recently been developed. This study examined the feasibility of using the Quality of Well-Being-Self-Administered (QWB-SA) questionnaire in an older population. METHODS: The Quality of Well-Being-Self-Administered questionnaire was sent to 430 community-dwelling individuals aged 65 years and older who were randomly selected from primary care physicians' offices. Response patterns, scaling distributions, and the acceptability of the survey were examined for all respondents. The results of the QWB-SA questionnaire were compared to the Sickness Impact Profile (SIP) and the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) for those individuals who also had completed the latter two surveys approximately 10 months earlier and whose health had not changed substantially in the meantime. RESULTS: Three hundred and one older adults (70%) responded. The mean QWB-SA questionnaire score was 0.7035. The scores were not skewed, and there were no floor or ceiling effects. The mean time to complete the QWB-SA questionnaire was 14.2 minutes, which was significantly shorter than for the SIP (19.3 minutes) but significantly longer than for the SF-36 (12.5 minutes). Subjects rated their satisfaction with the QWB-SA questionnaire somewhat lower than for the SIP and similar to SF-36. Correlations between the QWB-SA questionnaire and the SIP and SF-36 were moderate and were generally stronger for measures of physical health than for other domains such as mental health. CONCLUSIONS: The self-administered QWB questionnaire was acceptable to older respondents, and it correlated with other measures of health-related quality of life. It can be considered as a candidate for some research applications among older adults.

Aged↗
PubMed1998

Is work status of low back pain patients best described by an automated device or by a questionnaire?

STUDY DESIGN: A prospective cohort study of patients with subacute occupational back pain. OBJECTIVES: To study the relation between a marketed opto-electric device measuring trunk kinematics, a widely used specific functional capacity questionnaire, and work status in back pain patients, and to assess the responsiveness to change in work status of the opto-electric device and the questionnaire. SUMMARY OF BACKGROUND DATA: Several instruments have been developed to evaluate the functional capacities of patients with back pain, but the relation between these instruments and work status has rarely been studied. METHODS: The relation between the opto-electric device, the questionnaire, and work status in patients with back pain was evaluated. The study population was a prospective cohort of patients with subacute back pain who were absent from regular work for more than 4 weeks. All data were compiled blindly on the same day, at study entry (4 weeks after work accident), and at 12, 24, and 52 weeks after the work accident. The validity of the questionnaire and opto-electric device scores was assessed with partial correlation analyses, standardized response mean, logistic regression analyses, and receiver operating characteristics curves. RESULTS: The correlation between the questionnaire and opto-electric device scores was low. The questionnaire scores were significantly related to work status, but the opto-electric device scores were not. The questionnaire was responsive to change in work status, whereas the opto-electric device was not. CONCLUSIONS: The opto-electric device scores were not related to either functional capacity scores (questionnaire) or work status in patients with low back pain, and the opto-electric device was not responsive to change in work status. Conversely, the questionnaire was related to work status and was responsive to change in work status.

Activities of Daily Living↗
PubMed2006

Pediatric health-related quality of life questionnaires in clinical trials.

PURPOSE OF REVIEW: This review summarizes recent studies on the feasibility, reliability and validity of pediatric health-related quality of life questionnaires and gives an overview of recent applications of these measures in pediatrics. RECENT FINDINGS: The often-applied short form of the Child Health Questionnaire (CHQ-PF28) provides reliable physical and psychosocial summary measures, but reliable estimates for each scale require the longer version (CHQ-PF50). In addition to this questionnaire, the Pediatric Quality of Life Inventory is another reliable and valid measure. The TNO-AZL Preschool Children Quality of Life questionnaire is a feasible and reliable measure for preschool children. Generally, generic questionnaires are less sensitive to the impact of specific diseases than are disease-specific questionnaires. Parent and self-reports provide different outlooks on quality of life, which complement each other. SUMMARY: There are several feasible, reliable and validated pediatric quality of life questionnaires that can be used in clinical trials. These include generic and disease-specific questionnaires and health profile measures, as well as preference-based measures in pediatric settings. Generally, a combination of these types of questionnaires would be the most appropriate approach. Moreover, a combination of parent and self-reports should be applied. Appropriate selection of outcome measures will enhance the quality of pediatric studies and the ability to assess treatment effects in clinical trials.

Child↗
PubMed2005

The development of a symptom questionnaire for assessing virtual reality viewing using a head-mounted display.

PURPOSE: Virtual reality devices, including virtual reality head-mounted displays, are becoming increasingly accessible to the general public as technological advances lead to reduced costs. However, there are numerous reports that adverse effects such as ocular discomfort and headache are associated with these devices. To investigate these adverse effects, questionnaires that have been specifically designed for other purposes such as investigating motion sickness have often been used. The primary purpose of this study was to develop a standard questionnaire for use in investigating symptoms that result from virtual reality viewing. In addition, symptom duration and whether priming subjects elevates symptom ratings were also investigated. METHODS: A list of the most frequently reported symptoms following virtual reality viewing was determined from previously published studies and used as the basis for a pilot questionnaire. The pilot questionnaire, which consisted of 12 nonocular and 11 ocular symptoms, was administered to two groups of eight subjects. One group was primed by having them complete the questionnaire before immersion; the other group completed the questionnaire postviewing only. Postviewing testing was carried out immediately after viewing and then at 2-min intervals for a further 10 min. RESULTS: Priming subjects did not elevate symptom ratings; therefore, the data were pooled and 16 symptoms were found to increase significantly. The majority of symptoms dissipated rapidly, within 6 min after viewing. Frequency of endorsement data showed that approximately half of the symptoms on the pilot questionnaire could be discarded because <20% of subjects experienced them. CONCLUSIONS: Symptom questionnaires to investigate virtual reality viewing can be administered before viewing, without biasing the findings, allowing calculation of the amount of change from pre- to postviewing. However, symptoms dissipate rapidly and assessment of symptoms needs to occur in the first 5 min postviewing. Thirteen symptom questions, eight nonocular and five ocular, were determined to be useful for a questionnaire specifically related to virtual reality viewing using a head-mounted display.

Adult↗
PubMed2005

Quality of life assessment in laryngectomized individuals: do we need additions to standard questionnaires in specific clinical research projects?

OBJECTIVES: To assess, whether the EORTC questionnaires QLQ-C30 and QLQ-H&N35 give enough detailed information to study specific quality of life (QoL) related issues in laryngectomized individuals. DESIGN: Multicentre, prospective clinical trial; baseline measurement with EORTC questionnaires and an additional questionnaire, focusing on specific postlaryngectomy problems. SETTING: Head and Neck Department of one Comprehensive Cancer Center and three Academic Medical Hospitals in the Netherlands. PARTICIPANTS: Eighty laryngectomized individuals, selected to participate in a prospective clinical trial on hands-free tracheoesophageal speech. MAIN OUTCOMES MEASURES: Comparison of QoL dimensions, as assessed with the standard EORTC questionnaires, with the information obtained with additional questions, aimed at discovering in more detail, e.g. voice and respiratory problems in laryngectomized individuals. RESULTS: Based on the EORTC QoL questionnaires a good overall and voice specific QoL-level was found. However, the additional questionnaire showed that especially concerning voice and respiration more specific information was obtained. For example, despite an overall satisfaction with many aspects of the voice in more than three-quarters of the patients, speaking in a noisy environment was reported by 63% of the patients as being a serious problem, and a significant relation could be established between pulmonary and voicing problems (r = 0.28, P < 0.05), something also undetectable with the EORTC questionnaires. CONCLUSIONS: These findings underline the necessity to develop and use more specific additional questionnaires as an adjunct to the existing EORTC questionnaires, when studying specific symptoms in laryngectomized individuals, especially in order to detect intervention related changes over time.

Aged↗
PubMed1993

Appraisal of dental anxiety and fear questionnaires: a review.

This article reviews and assesses six dental anxiety and fear questionnaires. The construct aimed at by the questionnaires, the data collected, their reliability, validity and normative scores are considered. Some attention is given to the correlations between the questionnaires, their ambiguity, the presence of manuals, and whether the questionnaires tap the three segments distinguishable on theoretical ground in dental anxiety/fear. All questionnaires are open to criticism. In the final assessment Kleinknecht's Dental Fear Survey is preferred to Corah's Dental Anxiety Scale. The latter, however, appears useful in getting a quick impression of anxiety and in evaluative studies. Three recently developed questionnaires, Stouthard's Dental Anxiety Inventory, Weiner's Fear Questionnaire and Morin's Adolescents' Fear of Dental Treatment Cognitive Inventory are considered promising, but for the last two instruments more data, in particular with regard to their validity, are needed. It is concluded that in dental anxiety research more than one questionnaire should be used and that it may be worthwhile to include other, non-anxiety questionnaires as well.

Dental Anxiety↗
PubMed2002

A parent completed questionnaire to describe the patterns of wheezing and other respiratory symptoms in infants and preschool children.

AIM: To develop a standardised and validated respiratory symptom questionnaire for use in epidemiological or follow up studies in infants and preschool children. METHODOLOGY: After initial design and development, the questionnaire was administered to two cohorts of subjects, one recruited from a respiratory clinic and the other from a postnatal ward. The two cohorts then repeated the questionnaire, two weeks apart. The qualities of the questionnaire were assessed. RESULTS: Response rate to the initial questionnaire was 100% for the clinic based cohort and 64% for postnatally recruited families (total number of subjects 114). Questions showed good to moderate short term reliability (weighted kappa scores 0.47-0.7; average correct classification rates 0.74-0.91). Four domain concept scores showed excellent internal consistency (Cronbach alpha scores 0.87-0.95). Using principal component factor analysis, four new domains were devised showing acceptable construct validity and internal consistency. Criterion validity was assessed using a respiratory physician based diagnosis of asthma (RPBDA) as the gold standard for comparison. All eight scales in the questionnaire could significantly distinguish between infants with RPBDA and well or mildly symptomatic subjects. CONCLUSION: We have developed a practical, acceptable questionnaire with eight concept domains for use in infants and preschool children. The questionnaire has strong construct validity and internal consistency with good short term reliability of questions. More detailed study of criterion validity and the responsiveness of the questionnaire is required using a larger population and including children with the different phenotypes of wheezy illness.

Child, Preschool↗
PubMed1985

Use of a questionnaire in general practice to increase the recognition of patients with excessive alcohol consumption.

A self administered questionnaire, the health survey questionnaire, was designed to detect excessive alcohol consumption and mailed to patients who were registered with two general practices. Replies were received from 2572(75%) of 3452 patients. Excessive consumption was taken as 42 units of alcohol per week or more for men and 21 units per week or more for women: 1 unit = approximately 10 g ethanol and is equivalent to a half pint of beer, one glass of wine, or one standard measure of spirits. One hundred and twenty men (11%) and 68 women (5%) were identified by their responses to the questionnaire as excessive drinkers. According to their responses, roughly half of these expressed some concern about their drinking. In the practice where a disease register was kept 18 patients had been recorded as heavy drinkers before the study, and an additional 74 were detected by the questionnaire. Within 12 months after the questionnaire survey three groups of respondents were reviewed: (a) the excessive drinkers, (b) those who indicated concern about drinking but did not exceed the limits for excessive consumption, and (c) a random sample of those who were in neither of these two categories. Patients in these three groups were interviewed in a standard fashion to determine their alcohol consumption. Breath alcohol measurement was also carried out and a blood sample taken for the estimation of mean cell volume, gamma glutamyltranspeptidase activity, and serum aspartate transaminase activity. There were highly significant correlations between estimates of consumption obtained by the questionnaire and those obtained at interview except among the women who were excessive consumers, whose responses to the questionnaire indicated levels of consumption that were much higher than those to which they admitted at interview. Stated weekly consumption at interview that was above the limits set for the study was used as the standard measure for comparing the questionnaire with the other indicators of excessive drinking. The questionnaire had a considerably greater estimated sensitivity in detecting male excessive consumers than any of the blood tests. Among the women it apparently performed less well, although the numbers stating excessive consumption at interview were small. Breath alcohol measurement was positive in only a few of the excessive drinkers. The use of this simple and inexpensive instrument is likely to prove widely acceptable to patients in general practice and should result in a considerable increase in the recognition by general practitioners of patients with excessive alcohol consumption.

Adolescent↗
PubMed1991

Investigating the proxy effect and the saliency principle in household based postal questionnaires.

STUDY OBJECTIVE: The aim was to investigate two possible sources of bias inherent in using a household based postal questionnaire, the "proxy effect", inaccurate reporting about characteristics of others, and the "saliency principle", reporting of only the most salient features. This is of importance in surveys concerned with screening the population to identify individuals with certain characteristics, and so possibly relying on one member of the household to reply on behalf of all others. DESIGN AND SETTING: A two stage survey of disablement in the population was undertaken. A first phase postal questionnaire was sent to 25,168 households in Calderdale, West Yorkshire, England, to ascertain the prevalence of physical disability and of troubles with the joints. The second phase comprised in depth interviews with a sample of individuals identified in the first phase as being disabled. RESPONDENTS: A total of 21,889 postal questionnaires were returned (87%) representing households containing 42,826 people aged 16 years and over. A disproportionately stratified random sample of 950 respondents reporting disability was taken in the second phase. Of these 891 were still available, and 838 (94%) were interviewed. MEASUREMENTS AND MAIN RESULTS: The postal questionnaire found that almost 29% of those who lived "alone" (without another adult) reported some level of disability, compared to only 10% of those who lived with others. The difference remained significant after standardisation. This apparent underreporting or "proxy effect" was present for reporting about disability overall, but not for severe disability (dependence on help of others), which suggests the operation of the "saliency principle". Reporting on joint troubles appeared to be affected by the proxy effect both for any joint problems, and when more than five joints were affected. Analysis of a small set of postal questionnaires from respondents who reported joint problems only at interview and where we could identify who had completed the postal questionnaire supports the hypothesis of a proxy effect; two thirds of the original postal questionnaires had been completed by a proxy. The results were further complicated by an interaction between reporting of disability and joint troubles: the greater the level of disability, the less likely the reporting of joint troubles. CONCLUSIONS: The findings have general implications for studies involving postal household screening questionnaires, and raises additional concerns about those that are multitopic in content. In surveys of symptoms and minor disability, a proxy effect is likely to be operative. This effect is not apparent for obvious and long standing problems such as dependence on others for help. However the interaction between the reporting of disability and joint symptoms carries important implications for the development of multitopic postal screening questionnaires.

Adolescent↗