SEARCH · PubMed Health

Results for “Control Groups”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 109 records · Page 6Linked to original sources

PubMed1995

[Neurologic development in premature infants under 33 weeks of gestational age: determination of risk of neurological abnormalities in a prospective regional survey with a control group].

AIM: The purpose of this population-based study was to compare the incidence of neurodevelopmental disability and its risk factors between preterm and full-term infants matched as control group. POPULATION AND METHODS: The preterm cohort included 203 infants born between 25 and 33 weeks of gestational age in the region of Franche-Comté (France) during a two-year-period. The control group included 196 full-term infants born in the same maternities. Survival up to the date of follow-up was 171/203 (84%) for preterms and 195/196 (99.5%) for full-term infants (uncorrected age, mean 12 months). Neurodevelopmental assessments were performed by pediatricians or physicians on 164/171 surviving preterms (96% follow-up) and 179/195 full-terms (92%). RESULTS: Thirty-two (19.5%) preterm infants had disability, ten of these (6%) showing severe disability. Five (2.8%) full-term infants had disability, one of these (.5%) having severe disability. Risk factors predicting a disability included in a multivariate approach: prematurity (odds-ratio [OR]: 7.8), maternal age > 37 (OR: 3.0), lack of profession for both parents (OR: 3.7), male gender (OR: 2.9). The pediatrician observed a disability more frequently than the physician (OR: 2.46). Likewise, risk factors predicting a severe disability included: prematurity (OR: 10.8), lack of profession for both parents (OR: 5.8) and monochorial twin-placentation (OR: 4.5). CONCLUSIONS: Prematurity is not the only risk factor to be taken into account for neurodevelopmental evaluation of premature infants, but its influence still remains widely predominant.

Child Development↗

PubMed2000

Establishing the efficacy and cost effectiveness of community intensive case management of long-term mentally ill: a matched control group study.

OBJECTIVE: The study attempted to identify whether chronic mentally ill persons after receiving intensive case management (ICM) could demonstrate improved inpatient service utilisation compared with a matched control group cohort. Costings were measured to observe whether the increase in providing intensive outpatient contacts would be offset by savings in reduced inpatient service utilisation. METHOD: Eighty ICM patients were matched on ICD-9 diagnosis, age, gender, length of illness, age at first inpatient and outpatient contact, marital status, educational level, employment status, country of birth, year of arrival to Australia and religion. Inpatient bed-days and outpatient contacts were recorded and compared 12 months prior to ICM treatment, 12 and 24 months after ICM using within/between group repeated measures analysis of variance. RESULTS: The ICM group demonstrate significant reductions in inpatient service utilisation both within the 12- and 24-month period after receiving ICM treatment. The cost differential by 24 months of treatment was $801,475 in favour of the ICM model. The increase in costs of outpatient contacts were offset by a significant reduction in inpatient service utilisation. CONCLUSION: When outpatient contacts averaged one contact a week for the duration of the study period no significant reductions in inpatient service utilisation was recorded, as demonstrated by comparison with the matched control group. By increasing outpatient contacts by 3-4 contacts a week, inpatient contacts reduced by 36.8%. ICM is an efficacious and cost effective way to implement community-based services to the chronically long-term mentally ill.

Adult↗

PubMed2000

The use of placebo control groups in the assessment of psychiatric drugs: an historical context.

The reliable evaluation of treatments intended for the management of psychiatric illness would not be possible without the use of placebo. Other types of control groups can provide useful information, but none are capable of adducing a finding as compelling and unambiguously interpretable as a statistically significant drug-placebo difference. Its epistemological advantage notwithstanding, the ethicality of employing a placebo control group has been increasingly challenged in recent years. Many who object to the use of placebo on ethical grounds assume, incorrectly, that there are fungible alternatives to the use of placebo in the assessment of psychotropic drugs. This essay attempts to explain, within an historical context, not only why placebo is irreplaceable, but why it is often so difficult to communicate its advantages to those unfamiliar with the epistemological aims and methods of controlled clinical trials.

Antipsychotic Agents↗

PubMed2001

Lesbians and their sisters as a control group: demographic and mental health factors.

Lesbians and their heterosexual sisters were compared on demographic variables and mental health subscales, so that the feasibility of using heterosexual sisters as a control group for lesbians could be investigated Lesbians were significantly more educated, more likely to live in urban areas, and more geographically mobile than their heterosexual sisters. Heterosexual sisters were more likely than lesbians to be married and homemakers, to have children, and to identify with a formal religion. There was no difference in mental health, but lesbians had higher self-esteem. When all respondents were included, bisexual women had significantly poorer mental health than did lesbians and heterosexual women. This is the first study to use sisters as a control group in lesbian research.

Adult↗

PubMed1986

Use of dual control groups to estimate false positive rates in laboratory animal carcinogenicity studies.

Tumor incidence data from 18 recently completed carcinogenicity studies utilizing male and female mice and rats were examined to determine if the frequency of significant (p less than 0.05) pairwise differences between the two concurrent control groups employed in these experiments exceeded chance expectation. Although marked study-to-study variability was observed for some tumors, no evidence of extra-binomial within-study variability between the two concurrent control groups was found. The total number of observed significant (p less than 0.05) paired-control differences was virtually identical to what would be expected from the usual binomial model assumptions; the corresponding overall observed (44%) and expected (47-50%) false positive rates were essentially the same. While one should not overgeneralize the implications of these findings, these results should lessen concerns that elevated false positive rates resulting from extra-binomial within-study variability might be adversely affecting the interpretation of long-term laboratory animal carcinogenicity studies. On the other hand, these results reaffirm the conclusions of other investigators that (particularly for commonly occurring tumors) more stringent evidence than an isolated p less than 0.05 effect should be required before an increased tumor incidence is regarded as biologically significant; otherwise, the study may have an unacceptably high false positive rate.

Analysis of Variance↗

PubMed1980

Running a weight control group: experiences of a psychologist and a general practitioner.

A weight control group is described, led jointly by a general practitioner and a clinical psychologist. Approaches employed included dietary advice, behavioural advice, and group support. Of the original 16 members (including one group leader), seven dropped out at an early stage and the reasons for this are discussed. All members were re-weighed at intervals up to 18 months after the beginning of the six-month intensive period. They were also interviewed by a psychological research worker a year after the start of the group. The results suggest that a combined dietetic and psychological approach to weight control is of value.

Adult↗

PubMed1980

Distribution of 23 elements in the kidney, liver and lungs of workers from a smeltery and refinery in North Sweden exposed to a number of elements and of a control group.

The levels of antimony, arsenic, cadmium, caesium, chromium, cobalt, copper, gold, iron, lanthanum, lead, manganese, mercury, molybdenum, phosphorus, rubidium, scandium, selenium, silver, tellurium, tin, tungsten and zinc in the kidney, liver and lungs of autopsy specimens from exposed workers in North Sweden, as well as from a control group, have been assayed quantitatively. The workers had been exposed to several elements and their compounds, e.g. lead, mercury, arsenic and cadmium, for long periods in arsenic, lead or selenium plants and in a lead or copper smelter. The chemical analysis was by neutron activation analysis and atomic absorption spectrophotometry. Median levels of antimony, arsenic, cadmium, chromium cobalt, lanthanum, lead or selenium in kidney, liver or lungs in the exposed worker group were found to be about 2 to 16 times as great as the corresponding levels for the control group. Long biological half-life values were observed for these elements, especially in lung tissue.

Aged↗

PubMed1987

[Doppler sonographic detection of reduced flow velocity in the celiac trunk of the newborn infant with patent ductus arteriosus Botalli compared to a healthy control group].

Pulsed doppler recordings were obtained in the truncus coeliacus in 12 premature born infants (gestational age 30.3 +/- 2.5 weeks) with the clinical signs of patent ductus arteriosus Botalli (PDA) and compared to a control group of 24 healthy infants (gestational age 40.5 +/- 5.3 weeks). In all children the maximal systolic velocity, the endsystolic and the enddiastolic velocity and the pulsatility-index were measured. The 24 healthy newborns showed the following velocities: Maximal systolic velocity: 77 +/- 16 cm X s-1; endsystolic velocity: 31 +/- 10 cm X s-1; enddiastolic velocity; 18 +/- 9 cm X s-1. The pulsatility-index was 0.75 +/- 0.11. In children with PDA the maximal systolic velocity was 72 +/- 21 cm X s-1, the endsystolic velocity 15 +/- 14 cm X s-1 and the enddiastolic velocity -5 +/- 8 cm X s-1. The pulsatility-index was 1.08 +/- 0.12. All infants with large PDA showed a significant decrease of the endsystolic velocity and enddiastolic velocity, whereas the pulsatility-index was significantly increased. The decrease of the endsystolic and enddiastolic velocity in infants with large PDA in comparison to the healthy control group may lead to hypoxemic-ischemic lesions of the intestinal organs. The increased incidence of necrotizing enterocolitis in premature infants with large PDA may be the result of hypoperfusion of the small bowel.

Blood Flow Velocity↗

PubMed1992

Open cholecystectomy: a control group for comparison with laparoscopic cholecystectomy.

Laparoscopic cholecystectomy is rapidly becoming accepted as the best method for the treatment of symptomatic cholelithiasis. Randomized clinical trials comparing laparoscopic cholecystectomy with open cholecystectomy are unlikely to be performed. In order to compare these two operations, surgeons need an historical control group of patients who have undergone a conventional open cholecystectomy. The aim of this study was to document a control group of patients having an open cholecystectomy and compare them with patients having a laparoscopic cholecystectomy. This was achieved by a retrospective study of all patients who had an open cholecystectomy from January 1985 to December 1989. Four hundred and fifty-seven patients, 345 women and 112 men, had a cholecystectomy. Exploration of the common bile duct (ECBD) was performed in 59 (12.5%) cases. The mean operative duration was 73 min for cholecystectomy and 118 min for cholecystectomy and ECBD. The shortest mean postoperative stay was for an elective cholecystectomy (5.3 days) and the longest mean postoperative stay was for urgent admissions requiring ECBD (12.0 days). Operative dissection was difficult in 14.1% of elective cases and 51.8% of urgent cases. Ninety-seven (19.5%) patients had an additional procedure, unrelated to cholelithiasis, at the same operation; 44 did not require laparotomy, 31 had interval appendectomies, and 22 other cases required laparotomy in order to perform the additional procedure. All but one patient required postoperative narcotic analgesia. The mean duration of narcotic analgesia was 2.3 days. The complication rate was 35.2% for cholecystectomy and 62.5% for ECBD. If pulmonary atelectasis is excluded as a complication, these complication rates fell to 6.8% and 20.1%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Head-injured patients and control group: implicit versus explicit measures of frequency of occurrence.

This study was conducted in order to investigate the possibility that effortful processes are involved in the retrieval stage of the putative automatic task-frequency judgment. Head-injured (HI) and control groups were tested on a frequency of occurrence task under explicit-intentional retrieval (i.e., frequency estimation) and implicit-unintentional retrieval (i.e., word-stem priming) conditions. Subjects were presented with a list of nouns that appeared once, three times, and six times. Following presentation, subjects were first given a priming task, then a recall task, and finally a frequency judgment task. Although the control group performed better than the HI group on recall and frequency judgment tasks, the groups did not differ on the priming task. The results are discussed in terms of the relationship between effortful and automatic memory processes.

Adolescent↗

PubMed1994

[Social support, disability, coping with stress and personality markers in patients with subjective chronic aural tinnitus and a clinical control group].

The inhibition of physiological habituation in patients with chronic aural tinnitus extends from the level of cellular processing to psychologic and psychosocial determinants. The following hypotheses were tested in 32 patients with chronic tinnitus and 30 patients of a comparable clinical control group: tinnitus patients differ concerning (1) the perception of social support, (2) a disposition to psychosomatic diseases, (3) coping with stress and (4) certain personality traits. Standard psychological tests were used as well as a detailed examination of at least 30 minutes. Results showed that the tinnitus patients statistically perceived less social support and more social distress compared to the control group. They also showed significantly poorer results in coping with stress. Increased social distress in a number of cases resulted in noticeable decompensation. Additionally, a disposition to psychosomatic disorders increased, so that conflicts arising expressed themselves in various functional diseases. In most cases psychiatric exploration showed a vocational or familial overcharge. In patients experiencing decompensation, close cooperation with a psychotherapist is required.

Adaptation, Psychological↗

PubMed2000

Eating behavior in Prader-Willi syndrome, normal weight, and obese control groups.

OBJECTIVE: Hyperphagia in Prader-Willi syndrome (PWS) is hypothesized to be due to hypothalamic dysfunction; thus the study of individuals with PWS might illustrate how hypothalamic dysfunction affects eating behavior. The aim of this study was to document the microstructure of the eating behavior in patients with PWS and to compare it with that of members of obese and normal weight control groups of the same age. STUDY DESIGN: Nine subjects with PWS (age, 10 +/- 4 years), 20 normal weight subjects (age, 12 +/- 3 years), and 20 obese subjects (age, 12 +/- 4 years) were served an excess lunch meal (hash) on a hidden scale built into a table and connected to a computer. The plate of food is placed on top of the scale, and when the food is eaten, the change in food weight is registered continuously. An eating curve is displayed online. After the meal, the eating data are fitted to a polynomial, and the computer calculates the amount of food eaten, time of consumption, eating rate (initial and total), and rate of deceleration. RESULTS: Subjects with PWS were found to have a longer duration of eating (P =.04) and a slower initial eating rate (P =. 01) compared with members of both obese and normal weight groups. In subjects with PWS, 56% of the eating curves were non-decelerating (linear or accelerating) compared with 10% of the normal weight group and 30% of the obese group (P =.02). CONCLUSION: The microstructure of the eating behavior in subjects with PWS differs from that of members of obese and normal weight control groups. Thus the eating behavior found in subjects with PWS might be due to decreased satiation rather than increased hunger.

Adolescent↗

PubMed2001

Screening for specialized columnar epithelium with methylene blue: chromoendoscopy in patients with Barrett's esophagus and a normal control group.

BACKGROUND: Barrett's esophagus is characterized by the presence of specialized columnar epithelium (SCE) in the distal esophagus and is a precursor for dysplasia and adenocarcinoma. Methylene blue is used to selectively stain this type of epithelium within the columnar lined distal esophagus (CLE). The goal of our prospective study was to investigate the staining pattern with methylene blue in patients with visible CLE and a control group with macroscopically normal gastroesophageal junction. METHODS: Chromoendoscopy of the distal esophagus with 1% methylene blue was performed on a total of 73 patients (51 with visible CLE, 22 normal control subjects). Biopsies were targeted toward stained or macroscopically abnormal mucosal areas. Unstained CLE was sampled by obtaining 4-quadrant biopsy specimens at 2 cm intervals. RESULTS: The targeted biopsy of stained areas provided histologic proof of SCE with a sensitivity of 98% and a specificity of 61%. The detection of SCE increased with this method in patients with visible CLE (75%), but SCE was also prevalent in the control group (73%). Areas that by their appearance raised a suspicion for dysplasia and adenocarcinoma were already endoscopically apparent in 3 of 4 cases before methylene blue staining and showed different staining patterns. CONCLUSIONS: Methylene blue staining increases the rate of detection of SCE, both in patients with visible CLE and with normal gastroesophageal junction. For detection of dysplastic or malignant areas it is important to look for visible mucosal changes.

Aged↗

PubMedDate not supplied

[Aggression and group dependence in asthmatic children and a control group].

We studied a group of 60 boys and girls, 30 were asthmatics and 30 were controls in order to know more about factors that influenced the psychodynamics of the asthmatic and non asthmatic child. Both groups received the child's Thematic Aperception Test. Human version (CAT-H) and its supplement (CAT-S). No significant statistical differences were observed in relation to aggression but there was a significant difference in dependence (p.05). There results suggest us that the asthmatic child has lack of self confidence and has to look for support in other people.

Aggression↗

PubMedDate not supplied

Mexican American, nurse practitioner, and lay control group beliefs about cause and treatment of chest pain.

This study compared the health beliefs of Mexican Americans concerning the specific symptom of chest pain to beliefs of a group of predominant culture nurse practitioners and a lay predominant culture control group. Two hypotheses were examined; The health beliefs of groups differ significantly with culture and the health beliefs of groups differ significantly with professional education. A 43-item structured questionnaire was developed, based on literature review and unstructured interviews with Mexican American respondents. the questionnaire was administered to three nonprobability samples of 30 subjects each: Mexican Americans, nurse practitioners, and lay controls. Significant differences were found between Mexican Americans and the predominant culture groups of nurse practitioners and lay controls on folk beliefs regarding chest pain. On some items significant differences between nurse practitioners and the lay groups of Mexican Americans and predominant culture controls were based on professional education.

Adolescent↗

PubMed2001

[Quality of life one year after laparoscopic fundoplication is close to that of a control group: prospective study].

AIM OF THE STUDY: Prospective evaluation of the quality of life of patients after laparoscopic fundoplication for gastroesophageal reflux disease (GERD). PATIENTS AND METHODS: The quality of life of 30 consecutive patients who underwent laparoscopic fundoplication was evaluated using the GIQLI (gastrointestinal quality of life index) questionnaire, which included 36 items in five different areas: digestive symptoms, physical condition, emotional reaction, social integration and medical treatment. Seventeen men and 13 women (mean age: 50.2 +/- 17 years (32-68) were included with a follow-up of at least 1 year and with complete data available. The quality of life was evaluated before surgery, and at 1 month, 3 months, 6 months and 1 year after surgery with a 100% follow-up. Thirty healthy volunteers representing an identical population (with respect to age, sex, BMI, profession, smoking, etc.) anonymously filled in the same questionnaire. The pre- and postoperative GIQLI scores of patients operated for GERD were compared with the GIQLI score of the control group. RESULTS: Preoperatively, the GIQLI score (87 +/- 9.5) was much lower than that of the control group (123.4 +/- 13.6) (p < 0.001). This score significantly improved 3 months and 1 year after surgery and was comparable to that of the healthy population (115.3 +/- 9.6 vs 123.4 +/- 13.6 [ns]). Improvements were reported mainly with respect to digestive symptoms and physical condition. Social integration was slightly modified. CONCLUSION: The quality of life of patients after laparoscopic antireflux surgery was greatly improved and was close to the level expected in an healthy population. However, the study demonstrated the possible presence of postoperative functional digestive disorders, although these symptoms were not considered as being uncomfortable, since the level of satisfaction was 96.6% (n = 29).

Adult↗

PubMed1999

[Activated protein C resistance in patients with central retinal vein occlusion in comparison to patients with a history of deep-vein thrombosis and a healthy control group].

BACKGROUND: The recently described "APC resistance" caused by a mutant form of factor V (factor V Leiden) is the most frequent cause of hereditary thrombosis. This study was carried out to investigate the association between activated protein C resistance and central retinal vein occlusion (CRVO). We evaluated the prevalence of APC resistance in patients with CRVO, patients with a history of deep-vein thrombosis, and a healthy control group. PATIENTS AND METHODS: We examined 107 patients with CRVO, 112 patients with deep-vein thrombosis and 70 healthy individuals. The test performed was a modified APC-resistance assay using factor V-deficient plasma. RESULTS: We identified APC resistance in 5.6 % of patients with CRVO and in 5.7 % of the control group. All carriers were heterozygous. In the deep-vein thrombosis group 23.2 % tested positive for APC resistance. Four patients were homozygous and 22 were heterozygous carriers. CONCLUSION: These results indicate that APC resistance has no major role in the pathogenesis of CRVO. Routine testing for the presence of factor V Leiden mutant in CRVO is not necessary.

Adult↗

PubMed1987

Comparison of survival of amiodarone-treated patients with coronary artery disease and malignant ventricular arrhythmias with that of a control group with coronary artery disease.

Although amiodarone is effective in the treatment of ventricular arrhythmias, it is associated with serious toxic effects. In addition, the prognosis of patients with malignant ventricular arrhythmias and coronary artery disease treated with amiodarone remains poor. The survival of 54 consecutive patients with angiographically documented coronary artery disease and symptomatic ventricular tachycardia or ventricular fibrillation treated with amiodarone was compared with that of 5,125 medically treated patients with coronary artery disease. The amiodarone group was older, with worse left ventricular function and more peripheral and cerebrovascular disease. The 1 year survival probability was 0.73 for the amiodarone group and 0.94 for the control coronary artery disease group. At 2 years of follow-up, the survival probabilities were 0.60 and 0.90 for the amiodarone and the control group, respectively. When the survival curves were adjusted for group differences in baseline prognostic characteristics (integrated as a previously published hazard score), there was no difference in the prognosis of the two groups. These findings suggest that treatment with amiodarone of malignant ventricular arrhythmias associated with coronary artery disease maintains patients on an underlying survival curve determined by the degree of myocardial dysfunction, clinical characteristics and coronary anatomy, and that amiodarone does not have a deleterious effect on survival.

Aged↗