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PubMed2001

Transcatheter interventions for the treatment of peripheral atherosclerotic lesions: part II.

Transcatheter endovascular procedures are increasingly used to treat symptomatic peripheral atherosclerosis. This second part of a two-part review assesses the existing supportive evidence for the application of recently introduced transcatheter treatments for lesions that cause cerebrovascular ischemia and stroke. Studies were identified via MEDLINE (January 1993 through April 1999) and reference lists of identified articles. When multicenter prospective randomized trials or other high-quality studies were unavailable, studies with at least 50 patients per treated group and a minimum follow-up duration of 6 months were included. For each application, the authors assessed the quality of evidence (efficacy, safety, and, where available, cost-effectiveness) and made recommendations with appropriate caveats. Although recommendations based on proven efficacy and cost-effectiveness cannot be made in general, the use of transcatheter therapies can be supported in specific circumstances based on expected reduction in procedure-related morbidity and/or mortality. It is hoped that the identification of deficiencies in the literature will inform and inspire critically needed research in this area.

Angioplasty, Balloon↗

PubMed1999

Urinary incontinence: occurrence, knowledge, and attitudes among women aged 55 and older in a rural Midwestern setting.

OBJECTIVE: To examine the occurrence, attitudes, and knowledge of urinary incontinence (UI) among older women in a rural setting. DESIGN: Client questionnaire. SETTINGS AND SUBJECTS: A randomly selected sample of community-dwelling women aged 55 years and older living in a rural midwestern state. INSTRUMENT: Participants completed several instruments, including an Incontinence Survey that queried primarily demographic data, an Incontinence Quiz that queried knowledge and attitudes toward UI, and specific questions related to its clinical and psychosocial consequences. METHODS: The questionnaire was mailed to 300 women whose names had been randomly selected from a seniors' group mailing list. MAIN OUTCOME MEASURE: The prevalence of UI among a group of community-dwelling older women as well as attitudes and knowledge concerning incontinence. RESULTS: One hundred twenty women returned the questionnaire, providing a response rate of 40%. Three of the 120 respondents were excluded because they did not answer the question pertaining to UI status. Of the 117 who did respond, 79 (67.5%) reported UI. Most of the respondents with incontinence categorized their UI as minor (81.9%), and 88% denied that incontinence had a significant impact on their lifestyle. Thirty-seven percent of the incontinent women sought treatment. When questioned about UI, over half of the 117 respondents incorrectly indicated that incontinence is a normal result of advanced age. Almost one third of the respondents incorrectly believe that most people become incontinent by the time they reach the age of 85. CONCLUSIONS: Misconceptions concerning the causes of and the availability of treatment for incontinence among community-dwelling women may have an impact on their decision to seek care for this typically remediable condition.

Aged↗

PubMedDate not supplied

Perceived benefits and barriers of increased fruit and vegetable consumption: validation of a decisional balance scale.

OBJECTIVE: To develop and validate scales to assess perceived benefits and barriers (decisional balance) for increasing fruit and vegetable consumption. DESIGN: A cross-sectional mail and telephone survey was conducted. SUBJECTS/SETTINGS: A total of 1200 Chinese households were randomly selected from the Singapore residential telephone listings, and 71% responded to the mail survey; 390 males and 406 females participated (mean age = 39.3). MAIN OUTCOME MEASURES: Decisional balance, stage of change, and fruit and vegetable consumption were measured. STATISTICAL ANALYSES PERFORMED: Using a split-half sample approach, developmental sample responses were analyzed by principal-components analysis and validation sample responses by confirmatory factor analysis. Analyses of variance were used to examine stage differences in decisional balance. RESULTS: Principal-components analysis indicated two components representing benefits (or pros) (Cronbach's alpha = 0.86) and barriers (or cons) (alpha 0.79) of change. Confirmatory factor analysis strongly supported the two-component structure (Goodness of Fit Index = 0.97). There was a shift from cons to pros being more important across the stages. The increase in pros across the stages of change (p < 0.0001) corresponded to a medium effect size, and the decrease in cons (p < 0.01) corresponded to a small effect size. IMPLICATIONS: Decisional balance scales may be used to guide interventions to influence fruit and vegetable consumption.

Adult↗

PubMed1999

Alcohol and smoking as risk factors in chronic pancreatitis and pancreatic cancer.

The aim of this study was to compare alcohol and smoking as risk factors in the development of chronic pancreatitis and pancreatic cancer. We considered only male subjects: (1) 630 patients with chronic pancreatitis who developed 12 pancreatic and 47 extrapancreatic cancers; (2) 69 patients with histologically well documented pancreatic cancer and no clinical history of chronic pancreatitis; and (3) 700 random controls taken from the Verona polling list and submitted to a complete medical check-up. Chronic pancreatitis subjects drink more than control subjects and more than subjects with pancreatic cancer without chronic pancreatitis (P<0.001). The percentage of smokers in the group with chronic pancreatitis is significantly higher than that in the control group [odds ratio (OR) 17.3; 95% CI 12.6-23.8; P<0.001] and in the group with pancreatic carcinomas but with no history of chronic pancreatitis (OR 5.3; 95% CI 3.0-9.4; P<0.001). In conclusion, our study shows that: (1) the risk of chronic pancreatitis correlates both with alcohol intake and with cigarette smoking with a trend indicating that the risk increases with increased alcohol intake and cigarette consumption; (2) alcohol and smoking are statistically independent risk factors for chronic pancreatitis; and (3) the risk of pancreatic cancer correlates positively with cigarette smoking but not with drinking.

Adenocarcinoma↗

PubMed1979

Lung cancer in Greater Bombay: correlations with religion and smoking habits.

The resident population of Greater Bombay was analysed for the incidence of lung cancer and other variables of possible significance to lung cancer incidence. During a 10-year period from 1964-73, 2177 lung cancer cases (1861 males, 316 females) were registered, from a population pool consisting of 5.24 million persons (3.07 million males, 2.17 million females). The average annual incidence of lung cancer was 13.6 per 10(5) males but only 3.3 per 10(5) females, age-adjusted to the Standard World Population. The incidence in non-Parsi males (14.0) was almost double the figure in Parsi males (6.8). There was however no significant difference in incidence between non-Parsi (3.8) and Parsi females (3.3). Time-trend analyses did not reveal statistically significant differences in the incidence of lung cancer in any particular (male or female) age group. The data from death certificates for the same 10-year period 1964-73, showed that the age-adjusted rates (standardized to the world population) were 11.0 and 3.3 per 10(5), for males and females, in the total population. In a retrospective study, 792 males with lung cancer (42.6% of 1861 male cancer patients) for whom detailed smoking history is available, were matched for age and community with randomly selected controls, obtained from the voters list of the Greater Bombay Corporation, and significant statistical association was found between tobacco smoking and lung cancer. All smokers appear to be at high risk (16.8) compared with non-smokers. The relative risk in bidi smokers was however 19.3, even higher than in cigarette smokers (896). Hindu, Muslim and Christian smokers are apparently at identical risks. A dose-reponse relationship was found in bidi and cigarette smokers.

Adolescent↗

PubMed1998

Documentation of children's vaccination status in child care centres in Victoria.

OBJECTIVE: To assess the record-keeping of child care centres in Victoria with respect to children's vaccination status. METHODOLOGY: A random sample of 113 centres from a list of over 800 registered Victorian child care centres received a mailed questionnaire on characteristics and policies of the centre, including documentation of attending children's vaccination status. RESULTS: The response rate was 86.7%; more than 95% of centres had children under two in care. Only 85% of centres kept any record of children's immunisation status, with smaller centres and class 2 centres (occasional care centres) significantly less likely to keep records. Records were updated irregularly. Fewer than half of the centres studied kept a record of whether children had been vaccinated against Haemophilus influenzae type b. CONCLUSIONS: Despite the importance of documenting children's vaccination status, many child care centres have failed to develop adequate systems to record or update records of children's immunisation. This makes exclusion during outbreaks of a vaccine-preventable disease difficult. The ongoing process of accreditation may eventually improve performance, but both legislation and a better educational strategy to improve practice in this area are needed.

Child Day Care Centers↗

PubMed2006

Association of 6-thioguanine nucleotide levels and inflammatory bowel disease activity: a meta-analysis.

BACKGROUND & AIMS: 6-Thioguanine nucleotide (6-TGN) levels have been proposed to correlate with inflammatory bowel disease (IBD) activity among patients treated with azathioprine or 6-mercaptopurine (6-MP). Previous studies, most with small sample sizes, yielded conflicting conclusions. Our aim was to pool the available data to provide a more precise estimate of the association between 6-TGN levels and IBD activity. METHODS: We searched Medline and PubMed (from 1966 to November 2004) and reviewed the reference lists of selected articles. Fixed and random-effects models were used to test whether mean/median 6-TGN levels differed among patients with active disease vs remission and whether 6-TGN levels above a threshold of 230-260 pmol/8 x 10(8) red blood cells were associated with clinical remission. When studies reported multiple 6-TGN threshold values, we used the data for the lower value. RESULTS: We identified 55 articles, 12 of which contained data sufficient for inclusion. The mean/median 6-TGN levels were higher among patients in remission than in those with active IBD (pooled difference, 66 pmol/8 x 10(8) red blood cells; 95% confidence interval, 18-113; P = .006), but with significant heterogeneity. Excluding the 1 outlier study eliminated this heterogeneity. Patients with 6-TGN levels above the threshold value were more likely to be in remission (62%) than those below the threshold value (36%) (pooled odds ratio, 3.3; 95% confidence interval, 1.7-6.3; P < .001), but with significant heterogeneity. Again, excluding the 1 outlier study eliminated this heterogeneity. CONCLUSIONS: Although prior studies yielded inconsistent conclusions, this analysis strongly supports that higher 6-TGN levels are associated with clinical remission.

Guanine Nucleotides↗

PubMed2005

National survey regarding the management of an intraoperatively diagnosed patent foramen ovale during coronary artery bypass graft surgery.

OBJECTIVE: With the increased use of intraoperative transesophageal echocardiography (TEE), patent foramen ovale (PFO) has become a common finding during routine coronary artery bypass graft (CABG) surgery. This survey was designed to study potential differences in the management of intraoperatively diagnosed PFO. DESIGN: A written survey. SETTING: US university and community hospitals. PARTICIPANTS: The authors randomly selected 50% of US cardiac surgeons listed in the Cardiothoracic Surgery Network Database (n = 734). INTERVENTIONS: A written survey was mailed to the participants. The survey questions included respondents' use of TEE during CABG surgery, examination for a PFO with TEE, and management of intraoperatively diagnosed PFO in the CABG surgery. MEASUREMENTS AND MAIN RESULTS: Overall, 64% of individuals (468/734) responded to the survey request. TEE is available in the primary institution of 98.6% of respondents and used to search for a PFO in approximately one third of all CABG surgeries. During planned on-pump CABG surgery, 27.9% of respondents always close an intraoperatively diagnosed PFO, whereas 10.2% of respondents never close an intraoperatively diagnosed PFO. During planned off-pump CABG surgery, 27.6% of surgeons never change their plan, and 11% of respondents always convert the procedure to on-pump CABG to close the PFO. The majority of respondents decide whether to close a PFO based on the size of the PFO, the right atrial pressure, and a history of possible paradoxical embolism. CONCLUSIONS: In the United States, TEE is used extensively during CABG surgery. There is significant variability in how intraoperatively diagnosed PFO is managed during CABG surgery.

Blood Pressure↗

PubMed2001

Relationships between drinking and type of practice among U.S. female and male attorneys.

The author investigated the relationship between drinking and type of practice among U.S. attorneys. Participants were attorneys from 2 large midwestern cities, chosen through stratified random sampling from bar-association membership lists. Type of law practice was related to whether the participants drank in business-related situations but not to the frequency or the quantity of consumption. The participants in solo, corporate, or government practices were more likely than were those in private group practices to report no business-related drinking in the past 30 days. Female and male attorneys in similar practices reported similar abstention rates and quantities of consumption in business situations, suggesting that occupational norms were strongly salient for both genders. Criminal trial work was related to drinking only for the women. Results are discussed in terms of the influence of occupational culture on drinking.

Adult↗

PubMed1986

Drug prescribing in paediatrics at a teaching hospital serving a developing community.

Drug prescribing for paediatric inpatients at a teaching hospital serving a developing community was investigated. A list of 695 patient record numbers was randomly generated from the 7637 children admitted over the period examined (9.1%). Prescribed drugs were computer-categorized and counted. Antibacterials (30.0%), vitamins, iron preparations and dietary supplements (20.0%), electrolytes (18.8%), analgesics (12.2%) and respiratory drugs (7.1%) comprised the most frequently-prescribed groups. The main (admitting) diagnoses of the sample were also classified. Infective diseases (42.0%), respiratory conditions (18.2%), perinatal disorders (14.9%) and nutritional deficiencies (9.9%) predominated. Data for individual drugs in the four dominant drug groups are presented. The margins between the top one or two drugs and the others in each therapeutic category are notable. Few drugs are extensively used. They include ampicillin, paracetamol, multivitamin syrup and Darrow's preparations. The implications of this picture in therapeutics are discussed.

Africa, Southern↗

PubMed2004

Pityriasis versicolor: quality of studies.

OBJECTIVE: To evaluate the quality of the published literature on the treatment of pityriasis versicolor and to compare this evaluation with the number of times the work has been cited. METHODS: A search was performed using MEDLINE (1966-2002) to find publications evaluating the treatment of pityriasis versicolor. Two reviewers evaluated each clinical trial according to a list of pre-determined criteria including randomization and blinding, prior sample size calculation, treatment regimen clearly explained, and well-defined efficacy parameters. A maximum score of 20 could be attained by each publication. A citation count was performed using the ISI Web of Science Database (http://www.isinet.com/isi/products/citation/wos/). RESULTS: A total of 94 studies were included in this analysis of quality. Studies with a score of 8 or more were considered to be high quality, and 61 studies were rated as high-quality studies (65%). There was no significant correlation between paper quality and citation count. CONCLUSION: It is important for investigators and clinicians to be aware of the design of a high-quality protocol, since such high-quality studies are more likely to reflect accurate efficacy rates. Also, it is important for the information on the design and conduct of the trial to be conveyed to the reader so that a meaningful comparison between the studies can be made.

Bibliometrics↗

PubMed2003

Wessex shopping basket survey - a structured approach to local food sampling.

The shopping basket approach to food sampling, in which ready-to-eat food items from a shopping list were sampled at premises chosen at random, was adopted by 15 Environmental Health Departments in the Wessex region. A total of 2037 samples were analysed over a 30-month period. The microbiological quality varied considerably between food categories, with gravy and stock samples giving the highest proportion of satisfactory results. Sliced meats, cooked rice and sandwiches gave the poorest overall results. Whilst the majority of unsatisfactory results were due to elevated levels of indicator organisms (Aerobic Colony Count, Enterobacteriaceae and Escherichia coli), unsatisfactory or potentially hazardous levels of pathogens (Staphylococcus aureus, Bacillus cereus, Clostridium perfringens or Listeria monocytogenes) were detected in 1% of samples. Salmonella was not detected in any sample. The shopping basket survey was considered to be a useful way of structuring local sampling, and the random selection of premises was found to be a considerable advantage over previous sampling plans. In addition, the survey drew attention to a number of microbiological problems with specific food types, leading to more detailed investigations.

Commerce↗

PubMedDate not supplied

Knowledge, uptake and availability of health and social services among Asian Gujarati and white elderly persons.

OBJECTIVES: To investigate factors affecting the uptake of health and social services by elderly Asian Gujarati. METHODS: Four hundred and five Hindu Gujaratis and 381 whites aged 65 years and over residing in Leicester were randomly sampled from the Leicestershire District FHSA list by a computerized method based on linguistic analysis of the patient's name. One hundred and fifty Hindu Gujaratis and 152 whites were interviewed with response rates of 72% for the Asian Gujaratis and 80% for the white groups. The outcome measures were the activities of daily living (ADLs), incontinence, auditory/ visual deficits, cardiovascular disease, cognitive impairment (measured by the Mini-mental State Examination), depression, use of GP and hospital services, knowledge of community health and social services, willingness to use, suitability and cultural accessibility. RESULTS: The poorer uptake of services by elderly Asian Gujarati could not be explained by better health. They were significantly more likely to be dependent in six of the 14 ADLs and had higher rates of diabetes and impaired vision. Significantly more Asian Gujaratis than whites lived with others (84 versus 52%, p < 0.0001) with a greater availability of alternative sources of help and support. The knowledge and understanding of services were significantly poorer in the Gujarati group; fewer Asian Gujaratis knew how to apply for services and of those applying, fewer had been successful. Where services had been obtained, the levels of dissatisfaction were higher in the Gujarati group. The literacy rates were low in the Gujarati sample with 79% being unable to read or write in English and 27% unable to read or write in their mother tongue. CONCLUSIONS: The lower uptake of services by elderly Asian Gujarati is not the result of better health but may be explained by greater family support together with a lack of knowledge of and dissatisfaction with what is available. Health services will need to reappraise and revise some of their practices if they are to cater adequately for this growing population with many needs as yet unmet.

Aged↗

PubMed2000

What terminally ill patients care about: toward a validated construct of patients' perspectives.

BACKGROUND: Citizens have conveyed to professionals that care at the end of life is less than optimal. Efforts to improve matters have tended to work in piecemeal fashion, on tangible more than personal aspects of care, and without the benefit of documented perspectives of those who face dying. Policy initiatives and clinical interventions need guidance from a broad framework that is validated by patients' perspectives. PURPOSE: Our goals were to: (1) assess the construct validity and stability over time of the portions of a conceptual framework that concern patients' subjective experiences; (2) develop a foundation for measurement of these personally meaningful factors; and (3) examine these factors' associations for potential clinical or policy significance. POPULATION: Patients were from six diverse geographical areas whose physicians judged their survival prognosis to be 6 months or less. Physicians who referred the patients were randomly selected from state and specialty association lists. METHODS: We used in-person survey methodology and multivariate analysis of patient responses. The analysis fell into two parts. Using exploratory factor analysis, we looked for evidence of discrete dimensions of experiences. Using regression analysis, we examined associations among them. RESULTS: Of 1,131 eligible patients, 988 were interviewed (87.4% response rate). Of 682 patients who survived to follow-up interview 4-6 months later, 650 were interviewed (95.3% response rate). Exploratory factor analysis identified 12 discrete factors (accounting for 55% of variance; maximum Spearman's p = 0.24), 8 of which met criteria for representing measurable dimensions (accounting for 46% of variance). These 8 were: patient-clinician relationship; social connectedness; caregiving needs; psychological distress; spirituality/religiousness; personal acceptance; sense of purpose; and clinician communication. Eigenvalues ranged from 1.45 to 6.30 and Cronbach's alpha from 0.63 to 0.85. The concordance between these dimensions and those in the proposed framework indicated that two dimensions required minor modifications and six were confirmed, providing evidence of good construct validity for this portion of the framework. The same dimensions were also evident at follow-up except that the first two above-listed loaded on one combined factor, clinician interaction (eigenvalues 1.83-7.92; Cronbach's alpha from 0.64 to 0.86). This provides evidence of the construct's stability over time. Clinical communication and patient-clinician relationship were associated (odds ratio [OR] 2.79, 2.31-3.36). Better clinician communication correlated with somewhat better personal acceptance (OR 1.10,1.02-1.19), and a better patient-clinician relationship correlated with less psychological distress (OR 0.84, 0.75-0.95). CONCLUSIONS: We conclude that: (1) Personally meaningful aspects of patients' experience of terminal illness can be represented in valid, multidimensional constructs that are stable over time; (2) They are measurable; and (3) Aspects of the therapeutic relationship appear to correlate with patients' experience of the dying process.

Journal Article↗

PubMed2006

The influence of socio-demographic factors, treatment perceptions and attitudes to living donation on willingness to consider living kidney donor among kidney transplant candidates.

BACKGROUND: Living donor, compared with cadaveric donor kidney transplantation, is associated with prolonged graft survival and increased life expectancy for patients with end-stage renal disease (ESRD). However, access to living donor transplantation remains variable. Our objective was to further our understanding of the factors associated with the willingness to consider living donor kidney transplant (LDKTx). METHODS: All patients from two tertiary care hospitals being assessed for a LDKTx (n = 81), and a random sample of patients on the waiting list for a cadaveric kidney transplant (CDKTx, n = 133) were invited to participate. A mail survey assessed participants' socio-demographic characteristics, and perceptions of dialysis, CDKTx and LDKTx. Multivariable logistic regression was used to assess the influence of these factors on willingness to consider LDKTx. RESULTS: Adjusting for patient age, employment status and number of close relatives, willingness to consider an LDKTx was independently associated with a lower perceived risk of peri-operative complications to the donor (adjusted OR 3.59, P = 0.02), the perception that the recipient would live longer following living donor transplantation (adjusted OR 4.34, P = 0.003) and greater perceived appropriateness of asking a family member to donate a kidney (adjusted OR 5.06, P = 0.007). CONCLUSION: Among the ESRD patients studied, adjusting for key factors that may be associated with access to LDKTx, perceptions about risks to the donor and benefits to the recipient were independently associated with a willingness to consider LDKTx as a treatment option. Provision of standardized comprehensible information about all treatment options to patients with ESRD may improve acceptance rates for living donor transplantation.

Adult↗

PubMed1998

Stroke incidence among white, black, and Hispanic residents of an urban community: the Northern Manhattan Stroke Study.

Stroke mortality is reported to be greater in blacks than in whites, but stroke incidence data for blacks and Hispanics are sparse. The aim of this study was to determine and compare stroke incidence rates among whites, blacks, and Hispanics living in the same urban community. A population-based incidence study was conducted to identify all cases of first stroke occurring in northern Manhattan, New York City, between July 1, 1993, and June 30, 1996. The population of this area was approximately 210,000 at that time, based on 1990 US Census data. Surveillance for hospitalized and nonhospitalized stroke consisted of daily screening of all admissions, discharges, and computed tomography logs at Columbia-Presbyterian Medical Center, the only hospital in the region, and review of discharge lists from outside hospitals, telephone surveys of random households, and contacts with community physicians, Visiting Nurses' Services, and community agencies. Stroke incidence increased with age and was greater in men than in women. The average annual age-adjusted stroke incidence rate at age > or =20 years, per 100,000 population, was 223 for blacks, 196 for Hispanics, and 93 for whites. Blacks had a 2.4-fold and Hispanics a twofold increase in stroke incidence compared with whites. Cerebral infarct accounted for 77 percent of all strokes, intracerebral hemorrhage for 17 percent, and subarachnoid hemorrhage for 6 percent. These data from the Northern Manhattan Stroke Study suggest that part of the reported excess stroke mortality among blacks in the United States may be a reflection of racial/ethnic differences in stroke incidence.

Adult↗

PubMed1991

Occupational exposure to electromagnetic fields and breast cancer in men.

Data from a population-based case-control study of breast cancer in men were used to examine the hypothesis that occupational exposure to electromagnetic fields increases the risk of breast cancer. Incident cases (n = 227) diagnosed between 1983 and 1987 were obtained from 10 population-based cancer registries of the Surveillance, Epidemiology, and End Results program of the National Cancer Institute. Controls (n = 300) were selected by random digit dialing and from Medicare eligibility lists. Exposure status, defined as ever having been employed in a job which has been classified as involving potential exposure to electromagnetic fields, was assigned without knowledge of case/control status. An elevated risk was found for any job with exposure (odds ratio (OR) = 1.8, 95 percent confidence interval (CI) 1.0-3.7), and risk was highest among electricians, telephone linemen, and electric power workers (OR = 6.0, 95 percent CI 1.7-21) and radio and communications workers (OR = 2.9, 95 percent CI 0.8-10). Risk did not vary with duration of exposed employment. The risk was highest among subjects who were first employed in jobs with exposure before the age of 30 years and who were initially exposed at least 30 years prior to diagnosis. These results lend support to the theory that electromagnetic fields may be related to breast cancer in men. The hypothesis warrants evaluation in women.

Adult↗

PubMed2002

Reporting participation in case-control studies.

Although low participation in case-control studies may threaten their validity, it is difficult to evaluate the potential problem of nonresponse across studies because the level of participation among subjects is not reported in a consistent manner. This commentary presents a proposal for standard reporting of the process by which control subjects are recruited to a study and the outcomes of recruitment attempts. We encourage authors to provide a description of the sampling frame, the method of selecting units from the frame, and the number of units selected. For each unit selected, an outcome should be classified into four broad categories: ineligible sampling unit, unable to determine eligibility, respondent not eligible, and respondent screened and eligible. Details should be provided in each category; these details would differ according to the method used to contact potential respondents (by random-digit dialing, by telephone from a list, in person, or by mail). The proportion who participated can be reported as the investigator sees fit, as long as reporting of the components is complete. The sampling frame and outcomes should be reported separately for various parts of the study, such as controls from different sources or those who gave biological specimens. Standardized reporting will allow an evaluation of the success of various methods in recruiting potential participants, and will contribute important information for assessing the validity of individual studies.

Case-Control Studies↗