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At least 19 recordsLinked to original sources
PubMed1987

Stress management for essential hypertension: comparison with a minimally effective treatment, predictors of response to treatment, and effects on reactivity.

Few studies of psychological interventions for essential hypertension have incorporated comprehensive coping skills treatment programs, evaluated the efficacy of such programs against credible, minimally effective controls, examined the effects of these interventions on pressor responses, or clarified the nature of person by treatment interactions. The present study examined the relative effectiveness of multimodal stress management training and a minimally effective treatment control (i.e. GSR biofeedback training) in the treatment of essential hypertensives' blood pressure at rest and in response to simulated stressful interpersonal situations. At the conclusion of an 8 week training period, stress management participants exhibited reliably lower resting diastolic blood pressure and tended to exhibit lower systolic pressure than controls. The former condition maintained their lower pressures through a 6-month follow-up period, but decreases in controls over follow-up rendered the conditions equivalent in blood pressure. No differences between conditions emerged in analyses on pressor responses. Stress management training was somewhat more effective for individuals scoring low rather than high on measures of trait anxiety and irritability.

Adult↗
PubMed1990

Binding properties of plasma vitamin D-binding protein and intestinal 1,25-dihydroxyvitamin D3 receptor in piglets with pseudo-vitamin D-deficiency rickets, type I: treatment effects with pharmacological doses of vitamin D3.

The effective treatment of the rachitic symptoms of pseudo-vitamin D-deficiency rickets, type I (PVDRI) by massive doses of vitamin D3 was examined. For this purpose, the affinities and the maximum binding capacities (Bmax) of the plasma vitamin D-binding protein (DBP) and of the intestinal 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) receptor for vitamin D3, 25-hydroxyvitamin D3 (25-OHD3) and 1,25-(OH)2D3, were investigated in normal piglets and in rachitic piglets that suffered from PVDRI. The piglets were 5 to 10 weeks old and of both sexes. The Bmax of plasma DBP for 25-OHD3 was 6.77 +/- 0.45 microM for PVDRI piglets and 7.30 +/- 0.41 microM for control piglets and showed no differences between the two groups. Equilibrium association constants (Ka) of DBP for 25-OHD3 were 4.3 x 10(8) M-1 for PVDRI piglets and 4.0 x 10(8) M-1 for controls and showed also no differences between the two groups. Similarly the Ka of DBP for 1,25-(OH)2D3 was also the same for rachitic and control piglets (1.45 x 10(7) and 1.54 x 10(7) M-1, respectively). Due to the lower circulating concentration of 1,25-(OH)2D3 in the plasma of rachitic piglets compared to that of controls its free metabolite index was significantly lower in rachitic (0.42 +/- 0.05 x 10(-5)) than in control piglets (3.63 +/- 0.30 x 10(-5)). The Kd and Bmax of the intestinal nuclear receptor for 1,25-(OH)2D3 of rachitic and control piglets were 0.31 +/- 0.05 and 0.33 +/- 0.05 nM and 674 +/- 103 and 719 +/- 123 fmol/mg protein, respectively, and were also not different between the two groups of piglets. It was concluded from these observations that the rachitic symptoms of PVDRI piglets resulted solely from the lower free 1,25-(OH)2D3 concentration in plasma compared to that of normal piglets. The relative affinities of the intestinal 1,25-(OH)2D3 receptor for vitamin D3 and 25-OHD3 were also measured. It was found that 50% displacement of 1,25-(OH)2D3 from the intestinal receptor of PVDRI and control piglets required a 220,000- and 245,000-fold excess of the free concentration of vitamin D3, respectively, and a 20- to 42- and 23- to 71-fold excess of the free concentration of 25-OHD3, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

How much 'better' is good enough? The magnitude of treatment effect in clinical trials.

OBJECTIVES: Among the various factors required to calculate sample size for clinical trials, the magnitude of treatment effect anticipated is an important component. The objective of this report is to present some of the complexities involved in selection of treatment effect size in clinical trials. As a framework for discussion, an analysis of published reports related to surfactant therapy was carried out. DESIGN: Twenty-one consecutive exogenous surfactant trials for neonatal respiratory distress syndrome were analyzed. The "Methods" sections were reviewed for evaluating various components of sample size calculation, including the anticipated treatment effect size. RESULTS: Sixteen (76%) of the 21 reports provided a description of sample size calculations, and 12 of these gave some reasons for the choice of the anticipated treatment effect size. Expressed as percent change, the median treatment effect from intervention anticipated by the investigators was 50% (range, 15% to 90%), with a positively skewed distribution. The actual median percent reduction in adverse events from treatment (as compared with baseline) was 36% (range, 75% reduction to 5% excess). When the treatment effect was expressed as difference in adverse event rate, in the 14 (of 16) trials that could be analyzed, the median observed reduction in adverse events (death, bronchopulmonary dysplasia, or occurrence of respiratory distress syndrome) was 14.5% (range, 52% reduction to 2% excess). All trials except one concluded, however, that the intervention was effective, mostly based on additional subgroup calculations. CONCLUSIONS: Researchers often select sample sizes capable of detecting only large treatment effects, thus risking type II error, although sometimes a much smaller effect could be clinically important. While pragmatic considerations must be considered during the design of randomized clinical trials, researchers ought to present a rationale for anticipating a given magnitude of treatment effect in their sample size calculations. It may be possible to consider innovative trial designs that help determine the most appropriate treatment choice with the least possible sample size.

Confidence Intervals↗
PubMedDate not supplied

Avoidance of large biases and large random errors in the assessment of moderate treatment effects: the need for systematic overviews.

In order to avoid selective biases and to minimize random errors, inference about the effects of treatment on serious endpoints needs to be based not on one, or a few, of the available trial results, but on a systematic overview of the totality of the evidence from all the relevant unconfounded randomized trials. But, only where coverage of all, or nearly all, randomized patients in all relevant trials (or a reasonably unbiased sample of such trials) can be assured, is a systematic overview of trials reasonably trustworthy, for then any selective biases are likely to be small in comparison with any moderate effects of treatment. Checks for the existence of such biases can best be conducted if reasonably detailed data are available from each trial. Future trials should take into account the results of any relevant overviews in their design, and should plan to obtain sufficient numbers of events to contribute substantially to such overviews. In many cases, this implies the need for randomized trials that are much larger than is currently standard.

Clinical Trials as Topic↗
PubMed1978

Simple, effective treatment of agoraphobia.

For effective treatment of agoraphobia both patient and therapist must understand the mechanisms of sensitization and self-desensitization. Rather than aiming to adapt to difficult situations, to achieve desensitization by suggestions, or to avoid panic, the agoraphobe must learn to pass through panic and to rid oneself of drug dependency. This method of self-desensitization will, as a rule, achieve results quickly and does not necessarily depend upon finding the cause of the original sensitization.

Adaptation, Psychological↗
PubMed2025

Unveiling non-small cell lung cancer treatment effect heterogeneity: a comparative analysis of statistical methods.

BACKGROUND: For patients with advanced non-small cell lung cancer lacking targetable genomic alterations, the impact of clinicogenomic characteristics on the effectiveness of combining chemotherapy with immunotherapy is unclear. METHODS: We evaluated 4 statistical methods for detecting heterogeneous treatment effects related to clinical factors, including programmed death-ligand 1 expression, tumor mutation burden, and stage at diagnosis, using the American Association for Cancer Research Project Genomics Evidence Neoplasia Exchange BioPharma Collaborative dataset supplemented with institutional data collected under the same data curation model. A 2-sided P value of no more than .05 was used to denote statistical significance for all analyses. RESULTS: The mixture model revealed 2 latent subgroups: in one subgroup, there was no meaningful treatment effect, with average progression-free survival (PFS) only 5% longer with immunotherapy alone (95% confidence interval [CI] = -19% to 35%); in the second subgroup, immunotherapy alone was associated with a 35% decrease in average PFS (95% CI = -59% to 2%), corresponding to a ratio in treatment effects of 1.62 (95% CI = 1.02 to 2.57). There was a marginal association between lower tumor mutation burden levels and membership in the subgroup with improved PFS following receipt of chemoimmunotherapy. The causal survival forest highlighted the importance of tumor mutation burden (variable importance ranking: 1) and programmed death-ligand 1 (variable importance ranking: 3) when assessing heterogeneity. In contrast, the accelerated failure time and Cox proportional hazards models did not detect any statistically significant heterogeneous treatment effects. In simulations, the mixture model identified heterogeneous treatment effects more frequently than other methods, especially with weak covariate relationships, demonstrating its utility for informing personalized treatment approaches. CONCLUSIONS: The application of novel statistical methods to large scale clinico-genomic databases offers an opportunity to more accurately identify heterogeneous treatment effects in some settings as compared to traditional statistical methods. Applying such methods to the AACR Project GENIE BPC non-small cell lung cancer data indicated a potential association between decreasing tumor mutation burden and improved outcomes with chemoimmunotherapy as compared to immunotherapy alone.

Humans↗
PubMed1988

Explanatory and pragmatic estimates of the treatment effect when deviations from allocated treatment occur.

In a randomized clinical trial comparing two treatments it can happen that certain patients receive the treatment other than that determined by random allocation. Significance testing is usually performed by 'intention to treat', that is, comparison of groups as determined by random allocation. The difference between the mean values of the outcome variable for these two groups estimates the difference in practical use between two treatment policies, corresponding to a pragmatic approach. An attenuation factor can then be used to obtain an estimate of the underlying difference in effectiveness between the two treatments, corresponding to an explanatory paradigm. Thus two distinct estimates are obtained; in many instances both are valid, but have distinct interpretations. Correspondingly, in planning sample size requirements when deviations from allocated treatment can be anticipated, the target treatment difference may be understood in either an explanatory or a pragmatic sense; for the sample size assessment method it is necessary to take this distinction into account.

Analgesics↗
PubMed1976

A modification of the Johnson-Neyman technique comparing two regressions, applied to treatment effects dependent on baseline levels.

Treatment effects can often depend on baseline (pre-treatment) variables. This is ignored in many studies, or else the relationship is removed statistically by analysis of covariance. The latter method, however, assumes that slopes are equal and also loses information on the base-line contribution. Instead, the Johnson-Neyman technique does not assume that slopes are equal and furthermore permits examination of the baseline contribution. The method was devised for education research and is here extended to biological studies. However, the method assumes that variances are equal for the regressions, which might not be always so. The mmodification proposed accommodates inequalities of variance, whether intrinsic to the regressions or resulting from differences in group size. The Johnson--Neyman technique is discussed in relation to alternative analyses and, in appropriate situations, is considered to yield more information. Furthermore, with the refinement described, it involves even fewer assumptions and becomes more powerful.

Biology↗
PubMed1988

Conceptual and methodological issues in comparative studies of psychotherapy and pharmacotherapy, II: Nature and timing of treatment effects.

This is the second of two articles on the conceptual and methodological problems involved in comparing the effectiveness of drugs and psychotherapy in the treatment of mental disorders. Part II focuses on differences between psychotherapy and pharmacotherapy in the nature of treatment effects and related goals for treatment, differences in the time course of treatment effects, and potential sources of bias in the research setting. In designing comparative studies of psychotherapy and pharmacotherapy, investigators should address methodological choices explicitly and consider the implications for interpretation of findings.

Follow-Up Studies↗
PubMed1987

Treatment effect of combined maxillary protraction and chincap appliance in severe skeletal Class III cases.

The present study was designed to evaluate the true treatment effects of the maxillary protracting appliance with chincap for skeletal Class III cases and to evaluate the difference of true treatment effects between the cases in which the maxilla was protracted from the first molars and the cases protracted from the first premolars. Cephalograms of 63 cases (the first molar protraction group--27 cases protracted from the first molars, the first premolar protraction group--36 cases protracted from the first premolars) treated with the combined maxillary protraction and chincap appliance were used. Template analysis was performed to evaluate the estimated treatment effects without growth change. Forward movement of the maxilla and backward rotation of the mandible were characteristic features of the estimated treatment effects in 63 cases. In comparing the two groups, the maxilla was displaced more anteriorly and rotated more upward and forward in the first molar protraction group. Therefore, the intraoral site of protraction should be selected by considering vertical dimensions of skeletal and dental structures, and the amount of forward displacement of the maxilla required in the treatment of the individual patient.

Adolescent↗
PubMed1979

Detection of a treatment effect when not all experimental subjects will respond to treatment.

Non-responders attenuate average response an inflate sample variance, reducing the power of standard parametric tests. A new Fisher's type randomization test, which has no parametric analogue, is recommended when not all subjects may be capable of responding to treatment. The new test was evaluated by Monte Carlo means and applied to drug abuse data and to virus titre data. In most trial applications the new test proved to be more sensitive to treatment effects than Student's t.

Animals↗
PubMedDate not supplied

Principles and pitfalls in the analysis of prenatal treatment effects in multiparous species.

Developmental studies often assess the effect of treatment of the pregnant mother on offspring. The use of multiparous species such as rats and mice in such studies creates a special set of design and analysis problems. These arise for two reasons. First, the availability of many offspring per litter tempts the experimenter to inflate sample size by treating scores from several pups per litter as independent observations. Second, large litter size seldom makes it practical to measure exposure effects in all offspring of an exposed dam. Such studies commonly involve two-stage sampling: Drawing a random sample of dams for treatment, then drawing a second sample of pups per dam for neurobehavioral measurements. In this article, such sampling was modeled by two different simulations. The first, a standard Monte-Carlo approach, sampled from random-normal distributions for litter mean and within-litter variability. The second simulation sampled without replacement from actual data on weight of all pups in a series of 39 nontreated rat litters. These mutually-supportive approaches demonstrate that litter effects, even over as few as three litters, are generally large and statistically meaningful. Consequently, statistical significance tests are sensitive to litter effects. Inflation of sample size by treating as few as 2 pups per litter as independent measurements can almost triple the nominal 0.05 alpha level. Furthermore, two-stage sampling increases the within-treatment error term and correspondingly reduces statistical power relative to one-stage sampling.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1985

Relationships between jaw pain and jaw muscle contraction level: underlying factors and treatment effectiveness.

EMG representations of jaw muscle contraction levels were measured in dental patients with TMJ problems in addition to history and physical evidence of bruxing and clenching, TMJ problems alone, bruxing and clenching, and no pain. Patients with TMJ problems plus bruxing/clenching had EMG levels similar to those with clenching and bruxing problems alone. These levels were far higher than those in the groups with similarly low TMJ problems alone and with no pain. The pain groups were normal for anxiety level and life stress. Although a third of the patients produced a conversion V pattern on the MMPI, no effect was seen on treatment effectiveness. All but a few of the mixed TMJ problem/bruxism/clenching patients and of the bruxism/clenching patients showed considerable reduction in pain through use of treatment oriented toward muscle tension awareness and relaxation. The group with TMJ problems and normal masseter muscle tension made little progress.

Anxiety↗
PubMed1991

Long-term treatment effects in patients with bilateral retinoblastoma: ocular and mid-facial findings.

A total of 99 patients with bilateral retinoblastoma who had been treated between 1965 and 1982 were reexamined in April 1988 to study the late effects of treatment. Their median age at the follow-up visit in 1988 was 16 years (range, 6-27 years), and the median follow-up was 15 years (range, 6-26 years). All patients underwent a full eye examination, morphometric measurements of the mid-face and genetic counselling. Each eye or orbit and the corresponding side of the patient's mid-face were evaluated separately, resulting in 198 data sets from 99 individuals. Subjects were divided into four treatment groups according to whether photo- and cryo-coagulation, enucleation, radiation therapy or various combinations thereof were used. In all, 81 eyes had a visual acuity of greater than 0.4 (in 23 of these, however, only with low-vision aids). Within a dose range of 36-51 Gy, the location of the tumor (36%) or cataract (15%) were the main factors responsible for poor visual acuity, whereas radiation retinopathy and/or optic neuropathy occurred in only three cases. Cataracts were more frequently observed following orthovoltage as compared with megavoltage therapy (P = 0.012). A total of 72 eyes had been enucleated and had not received radiation therapy at any time. Cosmetic results (as measured by several parameters) in these cases were significantly better then those in 28 subjects who underwent combined radiation therapy and enucleation. As defined by various subjective as well as objective findings, mid-facial hypoplasia occurred significantly more often following orthovoltage as compared with megavoltage therapy.

Adolescent↗
PubMed1987

The Stockholm trial on adjuvant tamoxifen in early breast cancer. Correlation between estrogen receptor level and treatment effect.

The paper presents interim results of an on-going randomized trial of adjuvant tamoxifen (40 mg daily for 2 years) versus no endocrine adjuvant therapy in postmenopausal women with early breast cancer. A total of 1407 patients were included in the study between November 1976 through June 1984. Estrogen receptor (ER) data were available on 1184 patients (84%). The median follow-up was 53 months. Adjuvant tamoxifen increased the recurrence-free interval (P less than 0.01) but had no significant effect on overall survival. Treatment failures were reduced by 25% (P less than 0.01) and deaths by 7% (P greater than 0.05). Tamoxifen mainly decreased the frequency of loco-regional recurrence whereas distant metastases were less affected. The treatment effect was independent of tumor stage but was significantly related to the estrogen receptor (ER) content of the primary tumor. Tamoxifen appeared ineffective among ER negative patients, and the greatest effect was seen among those with high levels of ER. The results indicate that the main mechanism of action of adjuvant tamoxifen is similar to that suggested in advanced disease, i.e. an interaction with the estrogen receptor.

Aged↗