Fate of incorrectly addressed mailed questionnaires

Mail surveys are a widely used and often inexpensive method for conducting epidemiologic studies, but may suffer from poor response rates. Some of this nonresponse may be due to letters that never reach study subjects rather than nonparticipation. We mailed letters to invalid addresses and to fictitious occupants at valid addresses in order to determine the proportion of letters that were not returned to us by the postal service as undeliverable. All letters mailed to invalid addresses were returned, whereas 13.3% (95% Cl 2.0-24.7%) of letters sent to fictitious occupants were not. Because some undeliverable mail is not returned, investigators may erroneously assume nonresponse for some subjects who never have the opportunity to participate.     

The effect of access factors on breast screening attendance on two Scottish islands

The National Health Service Breast Cancer Screening Programme began in the Argyll and Clyde Health Board area in 1990. The Health Board area is large and includes 26 inhabited islands, thus necessitating the use of mobile screening units. This study examined factors affecting attendance for mammorgraphy on two islands in the west of Scotland, Islay and Jura, using these mobile screening units. The methods used were a prospective postal questionnaire survey prior to breast screening and personal interviews with attenders after screening. All 313 women who were invited to attend for breast cancer screening on Islay and Jura were sent the pre-screening questionnaire. Five were returned by the Post Office with incorrect addresses. Of the remaining 308 women, 234 (76%) returned the questionnaire, with a differential response rate of 84% for participants and 55% for non-participants. One hundred and sixty-three women were interviewed after attending for screening. Non-participants lived further from the screening site than participants (p < 0.01). Non-participants also tended to be in the oldest age group (60-64 years old) (p < 0.05). According to the post-screening interviews, 14% of participants travelled more than 30 minutes to the screening site. Attendance was lowest in the afternoon, when public transport was difficult to obtain. These results suggest that access has an important effect on screening uptake in remote and rural areas. Further consideration should be given to using more than one site in rural areas with long distances and limited public transport.     

Immediate psychiatric discharge letters by fax.

Much psychiatric care is provided outside the hospital setting. It is important for general practitioners (GPs) to have available information of good quality, provided promptly, after patients' discharges from in-patient psychiatric care to enable them to provide a high standard of follow-up care. In order to assess the value of hand-written Immediate Discharge Letters sent by fax we undertook a postal questionnaire survey of GPs, and examined a proportion of the clinical notes relating to 160 patients who between January and March 1998 had been discharged from in-patient care in the psychiatry admission wards at Crichton Royal Hospital, Dumfries. We found that structured letters, hand-written on a patient's discharge from in-patient status were generally valued by GPs as was their transmission by fax. Though certain deficiencies were confirmed in their completion, they are of value pending the arrival of a more definitive final discharge summary. We conclude that the continued use of such immediate discharge letters in psychiatry and their continued transmission by fax is justified.     

Vaccination and ill-health in dogs: a lack of temporal association and evidence of equivalence

Following concerns raised over the safety of canine vaccines, an epidemiological investigation was conducted to evaluate the evidence for a temporal association between vaccination and ill-health in dogs. The owners of a randomly selected population of dogs were sent 9055 postal questionnaires, 4040 of which were returned. No temporal association was found between vaccination and ill-health in dogs after adjusting for potential confounders, such as age. However, reliable inferences from non-significant test results are limited and so equivalence-testing methods were also used to make informative inferences. Results demonstrated that recent vaccination (< 3 months) does not increase signs of ill-health by more than 0.5% and may actually decrease it by as much as 5%. This general approach should be used in all field studies of vaccine safety.     

Possible factors affecting response to postal questionnaires: findings from a study of general practitioner services

Poor response rates affect the validity of results from postal questionnaires. The effect of three controllable factors upon response rates was examined in a recent study of patients' experiences and views of general practitioner services. The factors studied were the institution from which questionnaires were dispatched, the length of the questionnaire and the inclusion of a potentially sensitive question about ethnic origin. Questionnaires sent out by local Family Practitioner Committees were more likely to be returned than those sent out by a London-based independent research unit, but there were no differences in the nature of replies obtained. Neither the length of the questionnaire nor the inclusion of the potentially sensitive question affected response rates. The results of the study indicate that Family Practitioner Committees wishing to carry out postal surveys of users of general practitioner services can obtain satisfactory response rates.     

Personal values of male and female doctors: gender aspects

The aim of this study was to elucidate the personal values of physicians. It was part of the Physician 93 Study, the purpose of which was to shed light on the life situation, career and future plans of young doctors and their views on medical education. The survey population included all the medical doctors registered during the years 1982-1991 in Finland (N = 4671). In the spring of 1993 a postal questionnaire was sent to a random sample of 2341 doctors. After two reminder letters, 1818 questionnaires (78%) were returned. 59% of the respondents were women. Subjects were asked to rate on a 4-point scale each of a set of 17 potentially important values listed in the questionnaire, five of which were seen by the majority of physicians as very important. These values were: family life, health, close friends, success in work or in studies and children's success. The potentially important values were conceptualized as indicative of eight important dimensions of the values of physicians: close friends, health. self actualization, success, universal values, well-being, family and ideology. Women doctors rated close friends, health, success, universalism and ideology as more important than men doctors.     

Use of medication by Brazilian retirees: 2 - response rate and item completeness in a postal survey in Belo Horizonte, Minas Gerais State, Brazil

This paper reports on the response rate and completeness of item response in a self-administered postal survey questionnaire on use of medication by retirees 60 years or older under the Brazilian Social Security System, in Belo Horizonte, Minas Gerais State, in 2003. Questionnaires were sent in two rounds to 800 postal addresses of subjects selected by simple random sampling. The response rate was 47.8%, and there were no significant differences in the selected characteristics between respondents and non-respondents, or between early and late respondents. For almost all socio-demographic and health variables, item omission was less than or equal to 5% for both the entire sample and early or late responders. For all the medicines used, the dose and laboratory were the main items omitted. The findings indicate that details on drug use should be reevaluated in self-administered questionnaires.     

Increasing response to a postal survey of sedentary patients - a randomised controlled trial [ISRCTN45665423]

Background

A systematic review identified a range of methods, which can influence response rates. However, analysis specific to a healthcare setting, and in particular, involving people expected to be poor responders, was missing, We examined the effect of pre-warning letters on response rates to a postal survey of sedentary patients whom we expected a low rate of response.

Methods

Participants were randomised to receive a pre-warning letter or no pre-warning letter, seven days before sending the main questionnaire. The main questionnaire included a covering letter and pre-paid return envelope. After seven days, non-responders were sent a reminder letter and seven days later, another reminder letter with a further copy of the questionnaire and return envelope.

Results

627 adults, with a mean age of 48 years (SD 13, range 18 to 78) of whom 69.2% (434/627) were women, were randomised. 49.0% (307/627) of patients were allocated to receive a pre-warning letter and 51.0% (320/627) no pre-warning letter, seven days in advance of posting the main questionnaire. The final response rate to the main questionnaire was 30.0% (92/307) amongst those sent a pre-warning letter and 20.9% (67/320) not sent a pre-warning letter, with an adjusted odds ratio of 1.60 (95% CI 1.1, 2.30).

Conclusions

The relatively low cost method of sending a pre-warning letter had a modest impact on increasing response rates to a postal questionnaire sent to a group of patients for whom a low response rate was anticipated. Investigators should consider incorporating this simple intervention when conducting postal surveys, to reduce the potential for nonresponse bias and to increase the study power. Methods other than postal surveys may be needed however when a low response rate to postal surveys is likely.     

Yes Sir, no Sir, not much difference Sir

OBJECTIVE: To assess whether making the sender's knighthood explicit in a series of letters would have any detectable effect on the response. DESIGN: A random sequence was generated by flipping a coin to determine whether a letter would have 'Sir Iain Chalmers' or 'Iain Chalmers' typed under the signature. This sequence was prepared independently of the preparation of an alphabetic list of the intended recipients and was then used to determine which letter would be sent. The allocation could not be influenced by prior knowledge of the recipient. Two batches of letters were sent. SETTING: Medical royal colleges and associated faculties, and postgraduate medical and dental schools in the UK. PARTICIPANTS: Presidents and deans of medical royal colleges and deans of postgraduate medical and dental schools in the UK. MAIN OUTCOME MEASURES: Rates of response and the mean number of days between the posting of the original letter and the date on the response. RESULTS: No differences between the groups were detected in the response rates: 91% and 90% for 'Sir Iain Chalmers' and 'Iain Chalmers' (relative rate for response of 1.01, 95%CI 0.83-1.23, P = 0.92), or in the mean number of days to response ('Sir': 32 days; 'no Sir': 33 days). CONCLUSIONS: This finding is consistent with a systematic review of responses to postal surveys, in which the effect of the status of the signatory was investigated. Combining our result with the two trials that are most comparable to our study, in which letters from professors were compared with letters from students, gives a relative response rate of 1.00 (95% CI 0.91-1.10, P = 0.99). There is, therefore, no evidence from the existing randomized experiments that the status of the signatory has any impact on the likelihood or promptness of response-even if the status was conferred by the British monarch.     

Assessing the burden of undeliverable immunization reminder and recall notifications

Purpose

To assess the completeness and accuracy of parent contact information for the delivery of mailed reminder/recall notices using a statewide immunization information system (IIS).

Methods

The Michigan Care Improvement Registry (MCIR) was used to generate reminder and recall notifications for children ages 6 months–19 years in Michigan (2008–2009). Mailed notifications were classified as being undeliverable if they were returned to the local health department (LHD) by the US Postal Service.

Results

20,377 notifications were mailed and 5182 (26%) were undeliverable. Undeliverable notification increased with age (reference, 6–18 months): 19–35 months (OR = 1.27), 36–71 months (OR = 3.03) and adolescents 11–19 years (OR = 4.94). Children enrolled in Medicaid (OR = 0.76) were less likely to have an undeliverable notification compared to their non-enrolled counterparts, but children who had previously received some (OR = 1.07) or all vaccinations (OR = 2.43) at an LHD were more likely to have an undeliverable notification.

Conclusion

Undeliverable reminder/recall notifications are most likely among adolescents. Efforts to identify alternate sources of parent contact information may be an important strategy to improve the successful delivery of reminder/recall notifications, especially for adolescents.     

A comparison of response rate and time according to the survey methods used: A randomized controlled trial

The purpose of this study was to evaluate the effects of recorded and standard deliveries, and stamped and franked return envelopes in a postal survey of Korean–Vietnam veterans. Nine hundred veterans were randomly divided into four subgroups. A randomized controlled trial was conducted for two mailing strategies. The 52 study subjects to whom mail was undeliverable and 36 additional study subjects found not to be residing at the listed addresses were excluded from the study. The 699 (86%) surveys were returned within 39 business days after the first mailing. The response rate for the recorded delivery (88%) was significantly higher than that of the standard delivery (82%)(p = 0.03), and the response rate of the stamped return envelops (88%) was higher than that of the franked return envelops (85%)(p = 0.27). The replies for the recorded and standard deliveries arrived an average of 10.2 and 9.9 business days, respectively, after the first mailing (p = 0.60). The average times of the responses for the stamped and franked return envelopes were 9.8 and 10.4 business days, respectively (p = 0.25). Recorded deliveries significantly increased the response rate compared to standard deliveries, and stamped return envelops slightly increased the response rate a little compared to franked return envelops. The timing of response of recorded deliveries was similar to that of standard deliveries but the volume of response of recorded deliveries was higher than that of standard deliveries.This revised was published online in April 2005. In the previous version the article category was missing.     

Unsent Letters:

This paper presents an auxiliary tool to be used in social work supervision to help field work trainees to elaborate their feelings regarding their relationships with the client. The phenomenon of emotional blockages in worker-client relationships IS familiar to agency supervisors and teachers of field work. A technique for teaching trainees in field work to deal with difficulties of thts kind has been developed by the author. This technique consists in a written exercise in which the trainee composes a personal letter to the client that addresses itself to the problems in their relationship. These letters are not sent but used in supervision sessions for the benefit of the trainee.     

Participation in breast cancer screening: randomised controlled trials of doctors' letters and of telephone reminders

Abstract: The study used a randomised controlled trial to find out whether supporting letters from general practitioners accompanying the invitations from a screening centre affected participation in a population-based breast cancer screening program for women aged 50 to 64. A further randomised controlled trial compared the effect of postal reminders with telephone reminders for women who did not respond to an initial invitation to participate in the program. There were 482 women in the first trial and 641 in the second. Excluding women who were ineligible or could not be contacted, participation in screening was 71 per cent in the group which received letters from their general practitioners compared with 62 per cent in the group which did not receive letters (P = 0.059). In the group that received letters, 56 per cent were screened without a reminder compared with 43 per cent of the group that did not receive letters (P = 0.01). Fewer women who received letters from their general practitioners declined the invitation to be screened (P = 0.048). In the second trial, there was no difference in participation between the group receiving telephone reminders and the group receiving postal reminders. As in breast cancer screening programs in other countries, general practitioner endorsement of invitations increased participation in breast cancer screening. Postal reminders were as effective as telephone reminders in encouraging women who did not respond to an initial invitation to participate in screening.     

A confidence interval approach to investigating non-response bias and monitoring response to postal questionnaires.

STUDY OBJECTIVE--The aim was to develop an alternative method of investigating non-response bias in postal surveys, including a method of calculating a final full (100%) coverage confidence interval which avoids the wide intervals of existing approaches. DESIGN AND SETTING--As part of a two stage survey of disablement in the community, a first phase postal questionnaire was sent to 25,168 households in Calderdale, West Yorkshire, England. Confidence intervals were calculated to investigate the precision of estimates using a "no bias" model, where the prevalence in non-responders is assumed to be the same as in responders. RESPONDENTS--A total of 21,889 postal questionnaires were returned (87%), representing households containing 42,826 people aged 16 years and over. This was achieved by the original post (1st wave, 57% response); two further postal follow ups (2nd and 3rd waves, taking the response to 73% and 81% respectively), the latter including a small personal call back; and a final postal follow up (the 4th wave). RESULTS--The cumulative estimated prevalence of those with dependence was plotted as the survey progressed. The final wave full coverage estimated prevalence for those aged 16-64 years was 12.8 per 1000 with 95% confidence intervals of 11.3-14.4 per 1000. The integrity of this estimate holds as long as the true prevalence in non-responders is within the calculated non-response confidence interval under the no bias assumption, 9.7-16.0 per 1000 people. This latter interval represents the tolerance of prevalence in non-responders implied by the no bias assumption. CONCLUSIONS--The findings have general implications for monitoring non-response bias in postal screening questionnaires. The confidence interval approach developed in this paper offers an alternative to existing regression based estimates, giving an indication of the range of prevalence amongst non-responders that could be tolerated before the no bias assumption used by the model is breached. It is suggested that this approach can be used to determine both the extent of bias, and to aid decision making about the appropriate juncture to terminate follow up. It highlights the potential, particularly in the context of a computerised survey operation, of methodological investigation occurring simultaneously with survey operation.     

Prevalence of respiratory and hyperreactivity symptoms in relation to levels of criteria air pollutants in Sweden

Our knowledge of the adverse health effects from exposure tolow levels of air pollution is still Insufficient. Early indicators,such as respiratory symptoms, need more attention. We made useof the fact that possible weak effects can be detected moreeasily when the relevant exposure and other determinants arewell controlled. A postal questionnaire was sent to random samplesof inhabitants registered as residing in the vicinity of 55centrally located air quality monitoring stations in Swedishtowns. There were 6, 109 questionnaires (76%) returned. Multivariateanalyses with confounding control were used to examine the effectsof different levels of criteria pollutants on the prevalenceof symptoms. The ranges of the half year values were 9–32and 2–16 ug/m3 for nitrogen dioxide and sulphur dioxiderespectively. Logistic regression analyses showed higher risksfor respiratory problems such as coughs, throat irritation andnose irritation among the persons most exposed. The associationswere most obvious for nitrogen dioxide exposure among women.The suggested effects of air pollution exposure cannot be medicallyevaluated today but they are nevertheless interesting sincethey are found within common levels usually considered to besafe.     

Using mail to reach patients seen at an urban health care facility

Urban American Indians/Alaska Natives (AI/ANs) are highly mobile, and little is known about ways to include them in research or clinical activities. We evaluated postal mailings as a means of reaching patients seen at an urban Indian health care facility (60% of whom were AI/AN) and identified factors associated with receipt of mail. As part of a clinical trial, a Native art calendar was sent via first class mail to 5,633 clients seen at the urban Indian clinic during the prior two years. A multi-step address verification process was conducted, including telephone contacts, Web searches, and in-person visits. Logistic regressions examined the association of client characteristics with accurate addresses. Based on initial mailings and in-person location efforts, we estimated that only 61% of clients actually received the calendars. The multi-step address verification process was significantly less likely to identify working addresses for clients who were AI/AN and clients who were seen more than 3 months before the study. Reaching urban AI/ANs for research activities and health care is difficult. Innovative strategies are needed to locate this highly mobile and understudied population.     

Telephone reminders are a cost effective way to improve responses in postal health surveys

STUDY OBJECTIVE: To assess the effectiveness of a telephone reminder in increasing responses to postal surveys and to calculate the differential costs per completed questionnaire. DESIGN: Randomised controlled trial. SETTING: Australian university and rehabilitation medicine practice. PARTICIPANTS: The trial was conducted in 1999 among the 143 non-respondents to a questionnaire about work related neck and upper body disorders. The questionnaire was sent to two Australian female samples: 200 office workers (Sample A) and 92 former rehabilitation medicine patients (Sample B). A reminder letter, another copy of the questionnaire and a final letter were sent at two week intervals. Half of the non-respondents within each sample were randomly selected to receive a telephone reminder just after the second mailout of the questionnaire. All direct costs were calculated. MAIN RESULTS: Responses were significantly higher among those who received the telephone reminder intervention (relative risk 2.54, 95% confidence intervals 1.43 to 4.52). Analysed by intention to phone, 47% of non-respondents in Sample A and 38% in Sample B returned a complete questionnaire after the intervention, compared with 21% and 10%, respectively, in the control groups. For the 112 women (combined samples) who returned completed questionnaires before randomisation, the average cost per respondent was AUD14. There was a higher total cost for the intervention groups (AUD851 versus AUD386 for controls), but the significantly higher number of additional completed responses (31 versus 12) resulted in a 15% lower marginal cost per completed questionnaire in those groups. CONCLUSION: Telephone reminders are cost effective in improving responses to postal surveys.     

Portfolio use in general practice vocational training: a survey of GP registrars

BACKGROUND: Portfolios are increasingly advocated in medical education. Qualitative studies have suggested their value in stimulating experiential learning, promoting deep learning and encouraging reflection. This study explored the use of educational portfolios in reflective learning by general practice (GP) registrars in Yorkshire, England. METHOD: A postal questionnaire was sent to the 92 registrars of a deanery in November 2001, after a pilot study with registrars in a single district had been carried out. The questionnaire explored the registrars' use of the portfolio to collect information and for reflection, as well as registrars' attitudes towards the portfolio. It was returned by 71 registrars, representing a 77% response rate. Structured in-depth interviews were used to support the results obtained. RESULTS: Of the registrars who responded, 65% recorded information on a regular basis and 42% used the portfolio in reflective learning. Experienced registrars used the portfolio least. Those with supportive trainers used the portfolio more in reflection. CONCLUSIONS: The study suggests that the role of the trainer/supervisor is vital in portfolio-based learning. It raises questions about the acceptability of portfolio learning. It adds weight to the suggestion that careful introduction of portfolios and training of supervisors is vital. Further work to establish the role of portfolios in reflective learning is recommended.     

Chronic Fatigue Syndrome and Primary Fibromyalgia Syndrome as recognized by GPs

BACKGROUND: Prevalence studies on Chronic Fatigue Syndrome (CFS) are rare. Because of the similarity in symptoms, the prevalence of Primary Fibromyalgia Syndrome (PFS) was investigated at the same time. OBJECTIVES: To determine the prevalence of CFS and PFS as recognized by GPs in The Netherlands and to inform them of the existence of CFS. METHODS: A postal questionnaire was sent to all GPs. RESULTS: The questionnaire was returned by 60% of the GPs. Seventy-three per cent reported one or more CFS patients and 83% one or more PFS patients in their practice. CONCLUSION: The estimated prevalence of CFS as recognized by GPs of 112 (PFS 157) patients per 100,000 is a minimum estimate.     

Does anonymity increase response rate in postal questionnaire surveys about sensitive subjects? A randomised trial.

STUDY OBJECTIVE--The aim of the study was to determine whether complete anonymity improves the response rates to a postal questionnaire. DESIGN--The study derived from a series of postal surveys on AIDS knowledge conducted on six different dates in 1986 and 1987. The sample was randomly divided into two, each group being sent the same questionnaire. One group was informed that the replies were anonymous, the other that they were not. The latter were sent reminders. SETTING--Recipients of the questionnaires were drawn from the Southampton electoral rolls. PARTICIPANTS--300 people in each survey (total 1800) were sent questionnaires, representing on each occasion a different 1:500 systematic sample. RESULTS--Response rate was 49% for the anonymous questionnaires and 51% for the numbered questionnaires. Reminders boosted the response in the numbered group to 72%. CONCLUSIONS--There is no evidence that anonymity improves response to postal questionnaires, but the use of reminders may do so.