High Follow-up Rates Research Articles

Ethical issues in the conduct of longitudinal studies of addiction treatment

Many complex ethical issues arise in the day-to-day conduct of longitudinal studies of addiction treatment. These issues are rooted, in part, in the sustained and potentially ambiguous relationship between research staff and study participants, the frequently changing clinical and legal status of study participants, the assertive methods required to generate high follow-up rates, and the numerous systems of care and control in which participants are involved. To identify common ethical issues that arise in such studies, the authors conducted individual and group interviews with seasoned members (case trackers, field trackers, interviewers, and supervisors) of the research team. The ethical dilemmas identified through these interviews fell into seven broad arenas: (1) informed consent for research participation, (2) confidentiality and information disclosure, (3) relationship boundaries between study participants and research staff, (4) duty to warn/report responsibilities, (5) questions of autonomy and privacy, (6) issues related to compensation for research participation, and (7) data integrity. Case studies that illustrate common ethical dilemmas within each of these seven areas are presented and discussed. Ethical dilemmas in the study of addiction treatment can be effectively managed via ethically informed research protocols, staff training in ethical decision-making, monitoring and supervision, and collective debriefing of critical events.

Research fundamentals: follow-up of subjects in clinical trials: addressing subject attrition.

Many published clinical trials have less than adequate follow-up. When conducting a clinical trial, researchers attempt to minimize data loss; however, some data may not be collected, particularly when subjects are lost to follow-up. Careful planning of research protocols, including comprehensive initial data collection, identification of locators, flexible scheduling, systematic subject tracking, monitoring subject loss, and systematically approaching problem cases can ensure high follow-up rates. This article presents a compendium of techniques and procedures that researchers can use to enhance follow-up and address attrition in their studies. Finally, this article outlines statistical techniques that can be used to address the effects of missing data, particularly when patients are lost to follow-up.

Successful Techniques for Retaining a Cohort of Infants and Children Born to HIV-Infected Women: the Prospective P2C2 HIV Study

Retaining subjects from disadvantaged populations in long-term studies is necessary to obtain high-quality data. This article presents cumulative retention rates from a 5-year prospective cohort study, the Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection study. It also presents results of a cross-sectional qualitative survey about factors that induced caregivers to stay in the study. Although the repeated study visits were long and uncomfortable, cumulative retention among the 298 HIV-infected children was 80%. Incentives considered important by the caregivers included phone contact with nurse coordinators, nurse coordinators accompanying the caregiver and child during visits, phone reminders for appointments, help with scheduling, meals and transportation, access to health care, and relationships with staff. Thus, the high follow-up rate was in part due to nurses' efforts to reduce the study's burden on the families, provide tangible and intangible incentives, and establish personal relationships with families.

Limiting loss to follow-up in a multicenter randomized trial in orthopedic surgery

Even the best-designed, randomized controlled trials suffer when patients are lost to follow-up. Incomplete follow-up biases the results of a trial when patients who drop out are different from those who complete follow-up. This is exaggerated further when there are differential dropout rates between study groups. Previous randomized controlled trials in orthopedic trauma have reported up to 28% loss to follow-up. Only by striving to achieve a 0% loss to follow-up rate can we be certain that this type of bias does not affect our results. In our ongoing multicenter, randomized controlled trial comparing reamed and nonreamed intramedullary nailing of tibial shaft fractures, we have implemented several innovative strategies to minimize loss to follow-up. The exclusion criteria and consent process are designed to minimize losses. Study staff are carefully trained in communication and negotiation with patients. Additionally, a central methods center monitors all patient follow-up and aids in finding lost patients. Through these primary, secondary, and tertiary interventions, we have achieved 94% complete 1-year follow-up for the first 440 patients enrolled in the trial. Eleven patients withdrew consent, and we are unable to locate 17 patients. We have successfully minimized the loss to follow-up rate in our trial by incorporating innovative prevention and retention strategies into its design and conduct. Through planning, organization, and committing time and resources to minimizing loss to follow-up, other orthopedic trauma trials can hope to achieve the same high rates of follow-up.

Challenges encountered in measuring outcome for a rural psychiatric residential program

Evaluation of outcome measures can provide policymakers with valuable information on the effectiveness of psychiatric rehabilitation. Two specific challenges in collecting outcome measures for psychiatric rehabilitation programs are heterogeneity of outcomes and difficulty with follow-up. These two challenges were illustrated in the process of evaluating Rose Hill Center, a rural residential psychiatric rehabilitation program. The original design was to conduct interviews with former residents and family members and verify healthcare utilization. The difficulty of locating people and their reluctance to participate conspired to lower the follow-up rates. The design was modified to improve the follow-up rate but decrease the details of specific outcomes. The results showed a high but biased follow-up rate, with more information obtained for people who graduated from the program. The residents with planned discharge showed excellent outcomes in terms of living situation, working situation, healthcare utilization, and low severity of current symptoms. High compliance with medication spoke to the program's philosophy of including the residents in the decision-making process. The dual challenges of heterogeneity of outcomes and difficulty in follow-up that limit efforts to document the value of psychiatric rehabilitation are discussed.

Prevention and control of hepatitis B in China.

About 170 million Chinese are infected chronically with HBV and 10% suffer from chronic hepatitis. Around half a million Chinese die from hepatitis B caused hepatocellular carcinoma and endstage cirrhosis each year. From 1983 to the present, a controlled clinical trial involving 80,000 children on a universal hepatitis B vaccination programme to prevent chronic hepatitis, hepatocellular carcinoma, and endstage cirrhosis was implemented in Qidong, China. A pilot study demonstrated that the HBsAg rate reached the adult level before the fifth year of age, and neonatal vaccination with either plasma-derived or recombinant hepatitis B vaccines provided a similar 75% protective efficacy against HBV infection. The high rate of follow-up and blood tests coverage of the cohorts provided data to show 75% protection at the tenth to eleventh years of age against serum HBsAg and also against prolonged hepatic dysfunction. The strategy of controlling hepatitis B nationwide was based on the universal immunisation of newborns, beginning in cities and then the rural areas. The large-scale vaccine source was provided by domestic plants through technology transfer, first providing plasma-derived vaccine replaced completely by recombinant DNA vaccine in 1997. An official survey in 1999 using a cluster sampling of 25,878 children from 31 provinces reported an average coverage rate of three dose of hepatitis B vaccination of 70.7%, being higher in urban areas. The Ministry of Public Health of China has planned to integrate hepatitis B vaccination into the nationwide EPI program with Government-provided vaccines starting January 1, 2002.

Epidemiological challenges in studying the fetal origins of adult chronic disease

The relatively new research field of the fetal origins of adult disease has matured greatly in the past decade. Recent systematic overviews provide strong evidence that robust inverse epidemiological associations exist between birthweight and later blood pressure/hypertension 1 and glucose intolerance/type 2 diabetes. 2 Consistent associations are also evident for the inverse associations of birthweight with coronary heart disease incidence and mortality. 3,4 Studies with high follow-up rates and adjustment for social and economic variables have to a large extent mitigated earlier criticisms that observed associations were highly subject to confounding and selection bias. 5 Many questions remain, however, about the contributing roles of postnatal growth and development, underlying biological mechanisms, and the importance of the epidemiological findings to public health. This review outlines current challenges—stated in the form of propositions—that epidemiologists in this field currently face.

Post-discharge surgical wound infection surveillance in a provincial hospital: follow-up rates, validity of data and review of the literature.

Numerous studies suggest that many surgical site infections (SSI) come to light only after discharge from hospital. With increasing trends towards shorter length of stay and ambulatory day surgery, post-discharge surveillance may become necessary for all infection control programs, but the methodology has yet to be validated and standardized. The overall aim of the present study was to examine the impact of effective post-discharge SSI follow up on the overall SSI rate. A prospective targeted surveillance programme of 1291 surgical procedures was conducted at St John of God Health Care Geelong using the standardized National Nosocomial Infections Surveillance (NNIS) METHOD: Questionnaires were sent to surgeons and the results rigorously chased up. Factors giving rise to high follow-up rates and the relationship between follow up, attrition bias and validity of data were explored using a literature search. A post-discharge follow-up rate of 98.7% was achieved. When the post-discharge data were included, the overall SSI rate (6.0% (95% CI: 4.7-7.4)) was more than double that in hospital (2.7% (95% CI: 1.9-3.8)). An effective post-discharge follow-up programme significantly increased the SSI rate. From the authors' experience and a literature survey, possible ways to achieve high follow-up rates were suggested. It was also recommended that professional and regulating bodies in Australia be encouraged to standardize methodology and set minimum follow-up rates for post-discharge SSI surveillance. Increasing use of computerized hospital database systems for automated data gathering and processing should make this more practicable.

Pain and functional impairment 1 year after inguinal herniorrhaphy: a nationwide questionnaire study.

To determine the incidence of groin pain 1 year after inguinal herniorrhaphy and to assess the influence of chronic groin pain on function. The reported incidence of chronic pain after inguinal herniorrhaphy varies from 0% to 37%. No cross-sectional cohort studies with high follow-up rates have addressed this problem, and there is a lack of assessment of the functional consequences of chronic groin pain after herniorrhaphy. Two sets of self-administered questionnaires were mailed 1 year after surgery. The first established the incidence of chronic groin pain. The second characterized the pain and the effect of the pain on the function of those reporting pain. The study population comprised patients older than age 18 years registered in the Danish Hernia Database who underwent surgery between February 1, 1998, and March 31, 1998. The response rate to the first questionnaire was 80.8%. Pain in the groin area was reported by 28.7%, and 11.0% reported that pain was interfering with work or leisure activity. Older patients had a lower incidence of pain. There were no differences in the incidence of pain with regard to the different types of hernia, the different types of surgical repairs, or the different types of anesthesia. The second questionnaire was returned by 83%. Of these, 46 (4%) reported constant pain. The intensity of pain while at rest was moderate or severe in 40 (3%); with physical activity, pain was moderate or severe in 91 (8%). Impairment of specific daily activities as a result of pain was reported by 194 (16.6%). Pain characteristics were predominantly sensory, with a low use of affective terms. One year after inguinal hernia repair, pain is common (28.7%) and is associated with functional impairment in more than half of those with pain. These factors should be addressed when discussing the need for surgical intervention for an inguinal hernia.

Cervical intraepithelial neoplasia in pregnancy

To determine the progression/regression rate of cervical intraepithelial neoplasia in pregnancy and to describe the number of patients requiring treatment for cervical neoplasia during or following the pregnancy. A retrospective analysis of 305 pregnant women with abnormal cervical cytology was performed. The colposcopic, cytologic and histologic findings of repeated examinations during pregnancy and of the subsequent examination eight weeks postpartum were registered and compared. All smears were obtained by cotton bud and Cytobrush. Colposcopy was performed using standard techniques and cervical biopsies were taken in case of colposcopic abnormalities. Endocervical curettage was omitted during pregnancy. At postpartum evaluation colposcopy, directed biopsies and endocervical curettage were performed in all cases. One hundred and two patients (33%) were followed only by cytology and colposcopy. The remaining 203 patients (67%) had one to four colposcopically directed biopsies during the pregnancy. Comparing the initial histology in pregnancy to the postpartum histologic evaluation 25% showed spontaneous regression while 75% of the women exhibited progression (28%) or persistence (47%) in the severity of cervical neoplasia. Two patients were treated by cervical conization in early pregnancy and 143 women (53%) were treated within the first year after the pregnancy. In the postpartum period microinvasive carcinoma was diagnosed in two patients, but no women advanced to more serious stages of cervical cancer. The high persistence rate of cervical intraepithelial neoplasia in pregnancy leads us to recommend a liberal use of colposcopically directed biopsies during pregnancy and to ensure a high follow-up rate in the postpartum period.

Experimental Design and Methods for School-Based Randomized Trials: Experience from the Hutchinson Smoking Prevention Project (HSPP)

Nonadherence to accepted design principles for randomized trials has been a limitation of school-based intervention research. Designed to overcome these limitations, the Hutchinson Smoking Prevention Project (HSPP) is a 15-year randomized trial to determine the extent to which a school-based (grades 3–12) tobacco use prevention intervention can deter youth tobacco use throughout and beyond high school. This paper presents the HSPP experimental design, together with methods for its implementation, and an evaluation of the degree to which HSPP has adhered to principles of randomized trials. Results from the experimental design and its conduct include (1) a recruitment rate of 97.6% (40 of 41 targeted school districts), (2) full and active participation for the trial's duration by 100% of the 40 school districts recruited, (3) implementation by virtually all teachers (99%+), with 86% implementation fidelity, and (4) outcome determination for 94.3% (7910) of 8388 original study participants identified 12 years previously at baseline. The high degree of rigor achieved by the HSPP experimental design ensures confidence in the trial's soon-to-be available intervention effectiveness results. Equally important, for future school-based trials, the HSPP design and its execution have illustrated that school-based research can adhere to the principles of rigorous randomized trials, with high rates of implementation, and very high rates of recruitment, maintenance, and follow-up of study participants, even for studies with decade-long follow-up periods. Rigor in school-based trials can be achieved through a combination of (1) commitment to the principles of randomized trials, (2) attention to the special challenges of trials specific to the school setting, (3) adoption and meticulous execution of proven methods for trial conduct, and (4) establishment at the outset of principles for maintaining positive collaborative relationships with participating school districts for the duration of the trial. These findings are important in light of the great potential for using the nation's schools to access youth for health promotion/risk-factor prevention. Control Clin Trials 2000;21:144–165

How Well Do Patients Obtain Short-term Follow-up After Discharge From the Emergency Department?

Study objective: We sought to determine the follow-up rate of discharged emergency department patients who were instructed to obtain reevaluation within 48 hours at our ED, a clinic, or a private physician’s office and to determine the reasons why patients do not obtain short-term follow-up when instructed. Methods: Emergency physicians prospectively enrolled a convenience sample of patients discharged from a university hospital ED who were believed to be at risk for clinical deterioration. Patients were instructed to obtain reevaluation within 48 hours at a public clinic, private physician’s office, or our ED (without charge). A telephone interview was conducted after 48 hours had elapsed. Results: Three hundred twenty-five patients were enrolled, 300 were included in data analysis, and 203 (67.7%) of these obtained follow-up as instructed. Those referred to the ED had a higher follow-up rate (105/127 [82.7%]) than those referred to clinics (59/99 [59.6%]) or private physicians (39/74 [52.7%]). Inability to obtain an appointment was cited by 34.3% of those who did not obtain follow-up care as instructed. Conclusion: Many patients discharged from the ED who were believed to be at risk for clinical deterioration did not obtain medical follow-up within 48 hours when so instructed. Free ED follow-up resulted in a better rate of short-term follow-up than that for clinics and private physicians and may be especially useful if a patient’s ability to obtain follow-up is uncertain or if timely reevaluation is particularly imperative. [Barlas D, Homan CS, Rakowski J, Houck M, Thode HC Jr: How well do patients obtain short-term follow-up after discharge from the emergency department? Ann Emerg Med November 1999;34:610-614.]

Cholesteatoma in children—the experience at The Red Cross War Memorial Children’s Hospital in South Africa 1988–1996

This review of experience with cholesteatoma in children, describes the presentation and features of the disease from a tertiary institution in a ‘developing country’. A total of 24 out of 96 cholesteatomas in 81 children (M:F=44:37) aged 2–12 years initially presented with mastoiditis, with intracranial complications in seven children. Three of the cholesteatomas were congenital, 56 arose from retraction pockets—11 pars flaccida, 45 pars tensa—21 were associated with either a central perforation or total atelectasis and one originated at a ventilation tube site. Open cavity surgery was undertaken in all cases—atticotomy in 14, open mastoid cavity in 82 ears. It was not always possible to preserve reasonably normal pre-operative hearing nor was it possible to improve hearing loss. Twenty-six out of 81 children did not return for follow-up. Even with open cavity surgery, recurrence of cholesteatoma occurred. Late diagnosis, extensive disease, a high rate of complications and poor follow-up are the features of this disease in ‘developing’ countries.

Compliance With Disposition to Primary Care Physicians and Psychiatrists in Elderly Homebound Mentally Ill Patients

In a naturalistic study, the authors evaluated homebound mentally ill elderly patients as part of a psychiatric outreach team in two rural/semi-urban regions. Of the 80 patients evaluated in the two counties, 15 patients were admitted to nursing homes and were excluded from the analyses of follow-up data. Of the remaining 65 patients, 36 were referred to a primary care physician and 29 to a psychiatrist. The follow-up rate with primary care physicians (75%) was significantly greater than with psychiatrists (41% [P < 0.006]). At 3- to 6-month follow-up by telephone, patients who were compliant showed significantly greater clinical improvement than those who were not compliant (P < 0.0001). Overall, the higher follow-up rate for primary care physicians, compared with psychiatrists, reinforces the importance of educating and training primary care physicians in the diagnosis and management of mental disorders in elderly patients.

Methods of Ensuring High Follow-up Rates: Lessons from a Longitudinal Study of Dual Diagnosed Participants

Despite growing research interest in co-occurring psychiatric and substance misuse disorders, relatively few longitudinal studies have been conducted with dual diagnosis populations. Many of the longitudinal studies that have been done have experienced excessive attrition. Thus, investigators have noted that one of the primary difficulties of conducting longitudinal studies with this population is successfully minimizing attrition during follow-up. This study, conducted in 1991-1993, describes retention and tracking methods employed in a longitudinal study of 485 dual diagnosis participants. Follow-up interview completion rates at the 2-, 6-, 10-, 14-, and 18-month interviews were 86.7, 85.6, 85.1, 84.5, and 88.4%, respectively. Several case studies are provided that document some of the challenges facing project staff and successful strategies for handling them. A notable finding from this study was that participants reported that the relationship established with the interviewer was more important than material incentives in preventing study attrition.

Brief Physician Advice for Problem Drinkers-Reply

In Reply. —We appreciate Dr Bradley's comments regarding the differences in hospital days between the intervention and control groups reported in our article. It is important to clarify that the health care utilization data were based on patient self-report. We also collected utilization data from medical records, claims data, and family member corroborative interviews, but we opted to delay presenting this information until the 48-month follow-up of our study is completed in 1998. The issue of multiple comparisons probably is not a factor because the statistical differences between the groups were large, and the total number of outcome variables, based on previous alcohol treatment trials, was 9. Although bias is always a concern, our trial used randomized controlled trial methods, had a large sample size, recruited subjects from community practices, and had high follow-up rates. In addition, the analysis followed intention-to-treat procedures. Bradley also noted the potential bias of patient self-report. Health

A predictive method for estimating the late angiographic results of coronary intervention despite incomplete ascertainment.

Investigations of coronary restenosis typically use late (4-6-month) angiographic end points. Since only 50-80% of patients generally undergo repeat angiography, however, restenosis for the population as a whole is usually estimated by assuming that nonrestudied and restudied patients are similar. If restudied and nonrestudied patients differ, incomplete angiographic follow-up can yield an erroneous estimate of restenosis. No suitable method has yet been devised to detect and correct these errors. We studied the clinical indications for angiographic restudy in an actual series of 301 treated lesions in 267 consecutive patients who underwent either Palmaz-Schatz stenting (126 patients) or directional coronary atherectomy (141 patients) at our institution. While only 249 (83%) treated segments underwent 4-6-month angiographic follow-up, all had clinical follow-up that described whether specific indications for restudy were present. Patients who had no clinical indications for such restudy were designated as having elective follow-up. In contrast, patients who had recurrent symptoms or positive exercise studies and were scheduled for repeat angiography at the independent recommendation of their referring cardiologist were designated as having nonelective follow-up. Mean late percent stenosis or binary restenosis rate (> 50% diameter stenosis) was determined for elective versus nonelective lesions that underwent follow-up angiography. These values were then used to input the behavior of the nonrestudied lesions according to their clinical status. From these imputations, a "predictive" model was developed to estimate the mean restenosis values that would have been found had the entire population actually undergone angiographic follow-up. Comparisons between the estimates of this predictive method and the traditional method that uses only the actual angiographic data demonstrate how alterations in various parameters influence the selection bias caused by incomplete angiographic follow-up. Of the 301 lesions available for follow-up, 100 of the 103 (97%) nonelective versus 149 of the 198 (75%, p < 0.001) elective lesions actually underwent angiographic follow-up. Mean follow-up percent stenosis (50% versus 27%) and the binary restenosis rate (53% versus 13%) differed significantly for the nonelective versus the elective lesions, respectively (both p < 0.001). Even at the fairly high (83%) angiographic follow-up rate, elective versus nonelective status was thus a confounder that caused differences between the restenosis rate estimated by the traditional (29.1%; 95% CI: 23.4, 34.7) and the predictive methods (26.3%; 95% CI: 21.4, 31.1). Larger (and even statistically significant) differences may be present under the conditions that exist in many current studies. Restenosis trials with < 90% angiographic follow-up suffer from selection bias. Traditional methods that analyze only the restudied patients fail to correct for the important confounding influence of the clinical status of the nonrestudied patients. By using this readily available clinical information about the nonrestudied patients, a predictive method may be developed that provides a closer estimate of the true restenosis behavior for the population as a whole.

Angiographic follow-up after internal mammary artery graft angioplasty

Internal mammary artery (IMA) grafts are increasingly being used in the treatment of coronary artery disease. These conduits have been shown to have a low frequency of atherosclerotic narrowing, a high long-term patency rate, and a substantial beneficial effect on the survival of patients undergoing surgical myocardial revascularization. 1–4 Because the patency of the IMA graft is critical to long-term patient survival, stenosis of this graft postoperatively is a major clinical problem. The low graft attrition rate has limited our knowledge of the role of percutaneous transluminal coronary angioplasty in the treatment of IMA graft stenoses. Documentation of the safety and efficacy of IMA graft angioplasty has been limited to isolated case reports and series involving small numbers of patients with low angiographic follow-up rates. 5–11 This study describes our experience regarding the clinical and angiographic outcome after angioplasty of IMA graft stenoses in a consecutive series of patients with a high rate of angiographic follow-up.

HOME DETOXIFICATION FROM ALCOHOL: ITS SAFETY AND EFFICACY IN COMPARISON WITH INPATIENT CARE

The safety and short-term effectiveness of home detoxification (HD) was investigated by contrasting rates of treatment completion and of complications of 41 service users with those of a retrospectively matched inpatient comparison group. The latter comprised patients of a detoxification unit matched for age, sex and degree of alcohol dependence with HD subjects. HD subjects had severe problems with alcohol--they averaged 28.7 on the SADQ, 4.6 serious alcohol-related problems in the previous 2 months, a GGT of 123.8 and 174.6 reported units of alcohol consumed in the week before treatment. A high follow-up rate was achieved for both HD subjects and their relatives; there was close agreement between clients' reports, carers' reports and breathalyser readings with regard to further alcohol consumption. The HD subjects were visited at home an average of 6.9 times over 6.15 days. Chlormethiazole was prescribed in 36 cases at an average maximum daily dose of 6.3 capsules--significantly fewer than for the inpatient group. Both rates of completion and complication were virtually identical in the 2 groups. It is concluded that these data suggest HD is equivalent in both its safety and immediate efficacy to more expensive inpatient care.

The results of tubal surgery in the treatment of infertility in two non‐specialist hospitals

The results of surgery for tubal damage, other than reversal of sterilization, were studied in two large hospitals. This is the first recent study from centres claiming no special expertise in this surgery. An unusually high follow-up rate was obtained. The term pregnancy rate for patients operated on for bilateral distal tubal occlusion was 4%. The success rate is lower than the lowest reported, overall success rates for each cycle of in vitro fertilization (IVF) and very much lower than cumulative term pregnancy rates for tubal surgery reported by most other authors. Patients with distal tubal occlusion but minimal adhesions had the best prognosis. Our results suggest that, provided in vitro fertilization is available, only those patients with good prognostic factors should undergo tubal surgery. These represent the minority of all patients with non-iatrogenic tubal blockage.