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Biomedical subjects

D Sackett

Publications and source records attributed to D Sackett.

35 records · Page 2Linked to original sources
PubMed1990

Prevalence survey of cytomegalovirus infection in children in Chengdu.

Cytomegalovirus (CMV) is a common worldwide perinatal infection. Although usually asymptomatic, it may cause deafness in up to 15% of these infants. A cross-sectional study was performed to determine the age-specific prevalence of CMV seropositivity in Chinese children and to determine if any risk factors for infection could be identified. In a two-stage sampling procedure, nine districts were randomly selected from 70 citizenship districts in Chengdu, Sichuan Province, People's Republic of China. Then, 1,950 households were randomly selected from 11,886 households and interviewed. Blood was obtained from all children aged less than seven years and assayed using an enzyme-linked immunosorbent assay method. A subgroup of sera was retested at the research laboratory and also sent to the National Reference Laboratory in Beijing. Kappa values for the test agreement with the reference laboratory and retesting within the study laboratory were 0.94 and 0.86, respectively. Seropositivity averaged 52% in those aged less than one year and 60% in those between four and seven years. A higher rate of seropositivity was observed in urban versus rural children (odds ratio (OR) = 2.55), breast feeding in urban areas only (OR = 1.87), and day care versus home care setting (OR = 1.59). High CMV seroprevalence, even in the first year of life, was observed in this population of well children in Chengdu, China. An association was observed between seroprevalence and residence, method of feeding, and day care attendance.

Bottle Feeding↗
PubMed1988

A clinician's guide for conducting randomized trials in individual patients.

In determining optimal treatment for a patient conventional trials of therapy are susceptible to bias. Large-scale randomized trials can provide only a partial guide and have not been or cannot be carried out for most clinical disorders. However, randomized controlled trials (RCTs) in individual patients (N of 1 RCTs) may in some circumstances provide a solution to this dilemma. In an N of 1 RCT a patient undergoes pairs of treatment periods (one period of each pair with the active drug and one with matched placebo, assigned at random); both the patient and the clinician are blind to allocation, and treatment targets are monitored. N of 1 RCTs are useful for chronic, stable conditions for which the proposed treatment, which has a rapid onset of action and ceases to act soon after it is discontinued, has shown promise in an open trial of therapy. The monitoring of treatment targets usually includes quantitative measurement of the patient's symptoms with the use of simple patient diaries or questionnaires. Pairs of treatment periods are continued until effectiveness is proved or refuted. The cooperation of a pharmacy is required for the preparation of matching placebos and conduct of the trial. Formal statistical analysis may be helpful for interpreting the results. The practical approach presented in this paper allows clinicians to conduct their own N of 1 RCTs.

Clinical Trials as Topic↗
PubMed1986

Determining optimal therapy--randomized trials in individual patients.

Although the treatment of an individual patient in routine clinical practice has been likened to an experiment, the method is so susceptible to bias that we have come to demand multi-patient, double-blind, randomized controlled trials on matters of efficacy. Unfortunately, such trials have not or cannot be carried out for many clinical disorders; even when they have been executed their results may be difficult to extrapolate to individual patients. To resolve this problem, we have begun to use double-blind randomized trials in which a single patient undergoes a series of pairs of treatments, consisting of one active and one placebo or alternative treatment per pair, with the order determined by random allocation. Appropriate treatment targets (signs, symptoms, or laboratory tests) are used as the measure of efficacy, and the trial is continued until efficacy is established or disproved. We describe such a trial, which resulted in a dramatically beneficial modification of treatment in a patient with partially reversible airflow limitation. We have established a clinical service that facilitates the widespread use of the method in our community.

Aged↗
PubMed1979

Warfarin sodium versus low-dose heparin in the long-term treatment of venous thrombosis.

Acute deep-vein thrombosis is usually treated with intravenous heparin for a number of days, then with oral anticoagulants for weeks to months. We have compared adjusted-dose warfarin sodium with fixed low-dose subcutaneous heparin in the prevention of recurrent deep-vein thrombosis. Sixty-eight patients with acute deep-vein thrombosis confirmed by venography were treated with intravenous heparin and then randomized to secondary prophylaxis. Nine of 35 patients receiving subcutaneous heparin, but none of 33 receiving warfarin sodium, had new episodes of objectively documented venous thromboembolism (P = 0.001). Seven patients on warfarin sodium experienced bleeding complications (of which four were major), as compared with no patients receiving subcutaneous heparin (P less than 0.005). Thus, adjusted-dose warfarin sodium is more effective than low-dose subcutaneous heparin in preventing recurrent venous thromboembolism, but its use is accompanied by a significant risk of bleeding.

Acute Disease↗
PubMed1976

Distribution of complement C3 variants in individuals with cystic fibrosis.

The gene frequency for slow and fast electrophoretic variants of complement C3 in Caucasian individuals with cystic fibrosis was similar to the values expected for unaffected controls, thereby ruling out a suspected differential involvement of these phenotypes with the disease. In one family, cystic fibrosis and complement C3 phenotypes segregated independently.

Complement C3↗
PubMedDate not supplied

Assessing the effectiveness of community screening programs.

Community screening programs seek to detect disorders or risk factors in seemingly healthy persons. The following seven guidelines for determining whether a screening program is likely to be effective are proposed and discussed: (1) Has the effectiveness of the program been demonstrated in a randomized trial? (2) Are efficacious treatments available? (3) Does the burden of suffering warrant screening? (4) Is there a good screening test? (5) Does the program reach those who could benefit? (6) Can the health system cope with the program? (7) Do persons with positive screenings comply with advice and interventions?

Community Health Services↗
PubMedDate not supplied

Improving searching skills and evidence retrieval.

OBJECTIVE: To evaluate the effect of a three-hour training session in formulating questions and searching databases. DESIGN: A randomised controlled trial and before and after study, with blinded outcome assessment. SETTING: Oxford University Medical School, first clinical year. SUBJECTS: Altogether 108 medical students were randomly assigned to an experimental group (54) or a control group (54), and all were given the task of searching for evidence around an ulcer related problem or a cardiac problem. Students in the experimental group were randomly allocated to research one of the two problems before training and the remaining problem afterwards. Control students received no training and were randomly allocated to search for evidence around either of these problems. MAIN OUTCOME MEASURES: Searching performance; the quality of evidence retrieved; student satisfaction. RESULTS: Training improved the students' search performance and the quality of evidence retrieved. Students' satisfaction with the training was high. CONCLUSIONS: A three-hour interactive training session improved the students' ability to search databases and retrieve evidence and was well received by the students.

Adult↗