Biomarkers for exposure to ambient air pollution--comparison of carcinogen-DNA adduct levels with other exposure markers and markers for oxidative stress.
Human exposure to genotoxic compounds present in ambient air has been studied using selected biomarkers in nonsmoking Danish bus drivers and postal workers. A large interindividual variation in biomarker levels was observed. Significantly higher levels of bulky carcinogen-DNA adducts (75.42 adducts/10(8) nucleotides) and of 2-amino-apidic semialdehyde (AAS) in plasma proteins (56.7 pmol/mg protein) were observed in bus drivers working in the central part of Copenhagen, Denmark. In contrast, significantly higher levels of AAS in hemoglobin (55.8 pmol/mg protein), malondialdehyde in plasma (0. 96 nmol/ml plasma), and polycyclic aromatic hydrocarbon (PAH)-albumin adduct (3.38 fmol/ microg albumin) were observed in the suburban group. The biomarker levels in postal workers were similar to the levels in suburban bus drivers. In the combined group of bus drivers and postal workers, negative correlations were observed between bulky carcinogen-DNA adduct and PAH-albumin levels (p = 0.005), and between DNA adduct and [gamma]-glutamyl semialdehyde (GGS) in hemoglobin (p = 0.11). Highly significant correlations were found between PAH-albumin adducts and AAS in plasma (p = 0.001) and GGS in hemoglobin (p = 0.001). Significant correlations were also observed between urinary 8-oxo-7, 8-dihydro-2'-deoxyguanosine and AAS in plasma (p = 0.001) and PAH-albumin adducts (p = 0.002). The influence of the glutatione S-transferase (GST) M1 deletion on the correlation between the biomarkers was studied in the combined group. A significant negative correlation was only observed between bulky carcinogen-DNA adducts and PAH-albumin adducts (p = 0.02) and between DNA adduct and urinary mutagenic activity (p = 0.02) in the GSTM1 null group, but not in the workers who were homozygotes or heterozygotes for GSTM1. Our results indicate that some of the selected biomarkers can be used to distinguish between high and low exposure to environmental genotoxins. (+info)
Development of patient satisfaction questionnaires: I. Methodological issues.
OBJECTIVES: To develop a method for conducting postal surveys of patients' views and experiences of general practitioner care and to produce an off the shelf tool for general practice audit. DESIGN: Prospective study of performance of two patient questionnaires assessing accessibility to services (questionnaire 1) and interpersonal aspects of care (questionnaire 2) in comparing general practices. SETTING: Five general practices in Newcastle upon Tyne. PATIENTS: 3800 patients aged 16 and over, 1900 randomly drawn from family health services authority lists for each practice (questionnaire 1) and 1900 drawn from practice records (questionnaire 2). MAIN MEASURES: Response rates and technical evaluation of performance of the questionnaires (reliability, item nonresponse, ineligible response, sensitivity, and validity). RESULTS: Response rate for questionnaire 1 was 77% (range 69% to 83%) and to questionnaire 2, 82% (77% to 86%). Analysis of respondents and nonrespondents showed that significantly more women, people aged 65 or more, and those consulting in the past six months returned the questionnaires. Technical evaluation indicated good face validity and content validity and good internal consistency. CONCLUSIONS: A standardised off the shelf tool for audit was developed, and it will be a valuable model for future audits in general practice. (+info)
Do postal questionnaires change GPs' workload and referral patterns?
OBJECTIVE: We aimed to determine changes in workload in general practice associated with the postal administration of a health needs questionnaire. METHOD: We carried out controlled before-and-after intervention study of the effects of delivering a postal questionnaire to assess needs for care for patients with arthropathies of the hip and knee, groin hernia and varicose veins, and to assess health service utilization, general health status and risk factors for cardiovascular disease. The setting was a seven-partner, fundholding, group practice in Avon. The subjects were patients registered with an NHS group practice situated in Backwell and Nailsea, Avon. The outcome measures were the frequency of consultation, home visits and night visits, reasons for consultation, referral to specialist agencies and patterns of prescribing. RESULTS: There was no significant difference between the study and control group in the year before and the year after the postal administration of the questionnaire with respect to changes in overall frequency of consultation, frequency of referral (including type of referral) and frequency of prescribing of non-steroidal anti-inflammatory drugs. In the study group there was a significant (P<0.05) reduction in the number of daytime home visits and prescriptions written for analgesics. Analysis of the records of those who had received a medical examination, in addition to a postal questionnaire, showed that there was no significant difference between the study and control group with respect to frequency of consultation, referral to outside agencies or items prescribed. CONCLUSION: Administration of a health needs questionnaire to patients registered with this general practice was not associated with an increase in consultation frequency or referral, or a change in prescribing patterns. No plausible explanation could be identified for the significant reduction in the number of home visits and prescriptions written for analgesics. It was concluded that these results were a statistical artefact. On the basis of the evidence from this study, GPs can be reassured that the administration of health needs questionnaires of the type used in this study will not result in any increase in workload or costs of care incurred by increased referrals to outside agencies or increased prescribing. (+info)
SF-36 scores vary by method of administration: implications for study design.
BACKGROUND: Previous research suggests that people respond differently to health status measures when data are collected by interview or self completion of a questionnaire. The objective of this study was to determine whether SF-36 health status scores differ systematically by method of administration. METHOD: A randomized cross-over study was carried out on 210 new attenders at general medicine, endocrinology, gastroenterology and urological out-patient departments. The outcome was the difference in SF-36 profiles comparing clinic based interviews with self completion at home by the same subjects. RESULTS: For seven of the eight variables of the SF-36 scores were lower in the self assessment, the differences being statistically significant in four of the eight comparisons. The largest differences were in role limitations due to emotional problems (difference 14.74, 95 per cent confidence interval (CI) 7.76-21.7) and social function (difference 7.21, 95 per cent CI 3.19-11.23). CONCLUSIONS: Clinic based interviews systematically exaggerate health status compared with self assessment. The difference is sufficiently large to underestimate the effectiveness of health service interventions when a clinic based pre-intervention and postal self completed follow-up design is used, unless adjustment is made for this systematic bias. (+info)
Increasing response rates for mailed surveys of Medicaid clients and other low-income populations.
Mailing surveys to low-income populations is often avoided because of concern about low response rates. In this study, the authors used a mailed survey of a low-income population to test whether $1.00 or $2.00 cash-response incentives were worth the expense and whether 2-day priority mail ($2.90 postage) would yield a sufficiently higher response rate than certified mail ($1.52 postage) to justify its cost. In 1994, 2,243 randomly selected families in subsidized health care programs in Pierce County, Washington, were randomly sent no incentive, $1.00, or $2.00 in the first of three mailings. For the third mailing, nonrespondents were randomly assigned to receive either certified or 2-day priority mail. After 4 weeks, the response rates were 36.7%, 48.1%, and 50.3% for the no-incentive, $1.00, and $2.00 groups, respectively. After three mailings, the cost per response was the lowest for the group that received $1.00. The response rate for the certified mailing (28.1%) was significantly higher than the rate for the more expensive priority mailing (21.7%). No incentive-related bias was detected. The authors concluded that the most efficient protocol for this low-income population was to use a $1.00 incentive in the first mailing and a certified third mailing. (+info)
Screening for hand osteoarthritis (OA) using a postal survey.
OBJECTIVE: The aim of this study was to determine the feasibility of screening for hand osteoarthritis (OA) using a postal survey. METHODS: Men and women aged 40-79, selected at random from a general practice in Nottingham, were sent a postal survey concerning arm pain. Subjects were asked to identify presence of any nodes, based on a diagrammatic example, and to document specific distal (DIP) and proximal (PIP) nodes. One hundred and thirty-nine subjects were subsequently assessed by a nurse metrologist, blinded to the subjects assessment. Subject-observer agreement was measured by calculating unweighted kappa (kappa). In addition, sensitivity and specificity were calculated, taking observer-identified nodes as the 'gold standard'. Intraobserver reproducibility was assessed on 10 subjects with nodes. RESULTS: Intraobserver reproducibility was reasonable at all sites (kappa>/=0.59). Of the 56 subjects with observer-identified 'any nodes', 40 subjects had correctly identified them (sensitivity 71.4%); with three subjects incorrectly identifying nodes (specificity 96.4%). Corresponding kappa was 0.70. Subject-observer agreement was higher for presence/absence of any DIP nodes than PIP nodes (kappa=0.67 and 0.36 respectively). As with nodes overall, specificity was high (100% and 96.6% respectively). Agreement was generally poor for specific joint involvement. CONCLUSION: A postal survey is a useful screening tool for identifying subjects with nodes. Although sensitivity may not be sufficient to permit assessment of prevalence of hand OA in the community, it has potential applications in terms of identifying and defining cases for further study. (+info)
Postal urine specimens: are they a feasible method for genital chlamydial infection screening?
BACKGROUND: A United Kingdom (UK) screening programme for Chlamydia trachomatis has recently been announced. Pilot projects involving the opportunistic testing of women attending health facilities are due to commence in several sites. There is a danger that this approach will fail to obtain adequate population coverage. The alternative--true systematic population screening--is generally assumed to be unfeasible. Studies in Denmark using postal urine specimens have challenged this assumption. No such studies have been reported from the UK. AIM: To assess the potential of urine specimens sent by post as the basis for a UK population screening strategy for genital chlamydial infection. METHOD: Two hundred patients (100 men, 100 women) aged 18 to 45 years were randomly sampled from the list of one urban group practice. Subjects were mailed an explanatory letter, a urine sample container, a sexual lifestyle questionnaire, and a prepaid return envelope. Non-responders were contacted by telephone; persistent non-responders were visited at home. Samples were tested for Chlamydia by DNA amplification and enzyme immunoassay. RESULTS: Sixty-four (32%) subjects were no longer living at their GP registered address. Of the remaining 136, 126 (93%) responded to the survey and 113 (83%) accepted the request for a urine sample and completed a questionnaire. Acceptance rates were similar for men and women and across age groups. Four samples (3%) were Chlamydia positive. CONCLUSION: Home mailed urine specimen collection in conjunction with a self-completed postal questionnaire is feasible. This could provide a viable basis both for determining population Chlamydia prevalence and for a UK Chlamydia population screening strategy. Overall cost effectiveness of such a strategy will depend on the cost of the test used. Comparative performance characteristics of the different currently available tests in this setting have yet to be fully determined. (+info)
Postal consent for upper gastrointestinal endoscopy.
BACKGROUND: Standards for good practice in clinical risk management issued by the Clinical Negligence Scheme for Trusts indicate that "appropriate information is provided to patients on the risks and benefits of proposed treatment, and of the alternatives available before a signature on a consent form is sought". AIMS: To investigate the practicability and patient acceptability of a postal information and consent booklet for patients undergoing outpatient gastroscopy. METHODS: Information about gastroscopy procedure, personalised appointment details, and a carbonised consent form were compiled into a single booklet. This was mailed to patients well in advance of their endoscopic procedure. Patient satisfaction for this new process was assessed by questionnaire. RESULTS: 275 patients received a patient information booklet. Of these, 150 (54.5%) returned the consent form by post when they confirmed their attendance; 141 (94%) had signed the form, and the other nine requested further information. Of the remaining 125 booklets sent out, 115 (92%) forms were brought back on the day of the investigation having been previously signed. The remaining 10 (8%) required further information before signing the form. An audit of 168 patients was used to test reaction to the booklet and the idea of filling in the form before coming to hospital; 155 patients (92. 2%) reported the information given in the booklet to be "very useful", and all reported it to be "clear and understandable". CONCLUSION: A specifically designed patient information booklet with integral consent form is accepted by patients, and improves the level of understanding prior to the investigation being carried out. (+info)