Assessment of Prognostic Factors in Clinical Medicine

Patients suffering from a certain disease generally differ greatly regarding the course of their disease. The identification of factors from which much of this variability between patients can be explained may be of great importance. The study of such prognostic factors in clinical medicine is usually done for a variety of reasons which to some extent may overlap each other. One of the reasons may be to better understand how the disease is likely to behave. It is hardly ever possible nowadays to study the pure natural history of a disease because usually some form of treatment will have been undertaken. The treatment often will be curative in intent, but may also be directed towards the relief of symptoms or avoiding or delaying these in case no curative treatment is available. It is known from their natural history that certain illnesses do not require treatment at all because they are self-limited processes. Knowledge about prognostic factors in such cases will make it possible to provide information to the patient about the probable duration and course of the disease. Knowledge of factors which are related to the outcome of disease may be helpful to physicians in understanding the mechanism of the disease. Such better understanding may assist in modifying treatment protocols, searching for new treatments or fonnulating strategies for the optimal use of expensive medical tests. Sometimes knowledge of prognostic factors may be of use to alter the course of disease by remedial action. This will particularly be so if these factors are elements of lifestyle such as diet, exercise or habits. For instance, patients with alcoholic liver cirrhosis who stop taking alcohol appear to have a better prognosis regarding survival as compared to those who continue drinking alcohol [Borowsky et ai, 1981]. Such scientifically based facts may be helpful in encouraging patients to change their drinking habits. Knowledge of prognostic factors often will be of importance in planning therapeutic trials. It may be desirable to evaluate certain therapies only in patients who belong to certain prognostic categories. Also the number of patients required in a randomized clinical trial depends on the distribution of prognostic factors among patients to be included in the study

The follicle-stimulating hormone (FSH) threshold/window concept examined by different interventions with exogenous FSH during the follicular phase of the normal menstrual cycle: duration, rather than magnitude, of FSH increase affects follicle development

According to the threshold concept, FSH concentrations need to surpass a distinct level to stimulate ovarian follicle growth. The window concept stresses the significance of a limited duration of elevated FSH levels above the threshold for single dominant follicle selection. The aim of this study was to investigate effects on follicle growth of increased FSH levels, differing in duration and magnitude of elevation, durin

Doppler flow velocity waveforms in the fetal cardiac outflow tract: Reproducibility of waveform recording and analysis

__Abstract__ Reproducibility of flow velocity waveform recording and analysis was studied at fetal cardiac level (ductus arteriosus, pulmonary artery and ascending aorta) in 42 normal pregnancies. The flow velocity parameters studied were the peak systolic velocity (PSV), acceleration time (ACT), acceleration velocity (ACV), average velocity (AV) and flow velocity integral (FVI). In each patient, two consecutive measurements were performed (time delay 15 min) and of each measurement two hardcopies were analysed. A high reproducibility was achieved for the PSV, AV and FVI in all vessels studied; the coefficients of variation between readings of hardcopies were ≤3%, and the coefficients of variation between tests within patients were ≤7%. A moderate reproducibility was achieved for the ACT in the ascending aorta and pulmonary artery; the variation between tests was large for the ductus arteriosus. The reproducibility of the ACV was poor

Endoscopic versus open subfascial division of incompetent perforating veins in the treatment of venous leg ulceration: A randomized trial

AbstractPurpose: Subfascial division of incompetent perforating veins plays an important role in the surgical treatment of patients with venous ulceration of the lower leg. To minimize the high incidence of postoperative wound complications after open exploration, endoscopic approaches have recently been developed. We carried out a prospective, randomized comparison of open and endoscopic treatment of these patients that was aimed at ulcer healing and postoperative wound complications. Methods: Patients with current venous ulceration on the medial side of the lower leg were randomly allocated to open exploration by the modified Linton approach or endoscopic exploration by use of a mediastinoscope. Results: Thirty-nine patients were randomized, 19 to open exploration and 20 to endoscopic exploration. The incidence of wound infections after open exploration was 53%, compared with 0% in the endoscopic group (p < 0.001). Patients in the open group needed longer hospital stays (mean, 7 days; range, 3 to 39 days) than patients in the endoscopic group (mean, 4 days; range, 2 to 6 days; p = 0.001). Four months after operation, the ulcers of 17 patients (90%) in the open group and 17 patients (85%) in the endoscopic group had healed. During a mean follow-up of 21 months (range, 16 to 29 months), no recurrences were noticed in either group. Conclusions: Endoscopic division of incompetent perforating veins is equally as effective as open surgical exploration for the treatment of venous ulceration of the lower leg but leads to significantly fewer wound healing complications. Endoscopic division is therefore the preferred method. (J Vasc Surg 1997;26:1049-54.

Neonatal Procalcitonin Intervention Study (NeoPInS): Effect of Procalcitonin-guided decision making on Duration of antibiotic Therapy in suspected neonatal early-onset Sepsis: A multi-centre randomized superiority and non-inferiority Intervention Study

Background: Early diagnosis and treatment of the newborn infant with suspected sepsis are essential to prevent severe and life threatening complications. Diagnosis of neonatal sepsis is difficult because of the variable and nonspecific clinical presentation. Therefore, many newborns with nonspecific symptoms are started on antibiotic treatment before the presence of sepsis has been proven. With our recently published single-centre intervention study we were able to show that Procalcitonin determinations allowed to shorten the duration of antibiotic therapy in newborns with suspected early-onset sepsis.Methods/Design: The study is designed as randomized controlled international multicenter intervention trial on the efficacy and safety of Procalcitonin guided treatment. Term and near-term infants (gestational age ≥ 34 0/7 weeks) with suspected sepsis in the first 3 days of life requiring empiric antibiotic therapy will be included. The duration of antibiotic therapy in the standard group is based on the attending phy

A randomised study on the efficacy and safety of an automated Tru-Cut needle for percutaneous liver biopsy

BACKGROUND: We studied whether the theoretical advantages of a spring-loaded liver biopsy needle exist in clinical practice and if so if they are dependent upon the experience of the physician performing the biopsy. METHODS: In a stratified randomised study we enrolled 215 consecutive patients to compare the safety and efficacy of a new automatic biopsy gun (Acecut) with that of a standard Tru-Cut needle. RESULTS: A total of 464 biopsies were performed. The endpoints of the study were number of needle passes needed per patient, tissue yield of each needle pass and post-biopsy complications. The performance of the automatic needle was superior and more consistent with respect to tissue yield compared with the Tru-Cut needle (median yield 100% and 80%, respectively; p < 0.001). The difference was most marked for inexperienced physicians. There was no difference between the two needles in the number of passes needed. More post-biopsy pain and post-biopsy use of analgesics were observed in the automatic needle group (p = 0.04). CONCLUSION: The automatic Tru-Cut needle offers an advantage, particularly for physicians with no or limited experience in liver biopsies. However more post-biopsy pain and post-biopsy use of analgesics were observed in the automatic needle group

Doppler colour flow imaging of fetal intracerebral arteries relative to fetal behavioural states in normal pregnancy

In 14 normally developing term fetuses, the relationship between the blood flow velocity waveforms at cerebral arterial level (internal carotid artery, anterior, middle and posterior cerebral artery) and fetal behavioural states was studied using Doppler colour flow imaging. Behavioural state dependent changes in absolute flow velocities occurred in all vessels, except for the middle cerebral artery. These changes suggest preferential blood flow to the left heart resulting in increased flow to the cerebrum during fetal behavioural state 2F (active sleep) when compared with fetal behavioural state 1F (quiet sleep). The middle cerebral artery supplies the neocerebrum. This developing part of the cerebrum does not seem to take part in the regulation of fetal behaviour. In the internal carotid artery, an inverse relationship between peak systolic velocity and fetal heart rate could be established, which can be explained by a shorter rapid filling phase at raised fetal heart rate according to the Frank-Starling Law

Three-dimensional sonographic measurement of normal fetal brain volume during the second half of pregnancy

Objectives: This study was undertaken to develop a three-dimensional (3D) ultrasound method of measuring fetal brain volume. Study design: Serial 3D sonographic measurements of fetal brain volume were made in 68 normal singleton pregnancies a

Vibration therapy reduces CPAP need in a prospective randomised controlled trial

Background: Increased mucus production is a common phenomena following ventilatory support, which might increase morbidity. In order to reduce airway obstruction we tested the effect of vibration therapy on the duration of ventilatory support. Methodology: We conducted a randomised control study in a level IIIC NICU (28 beds) of a university hospital. Compared were nonactive techniques to vibration therapy in preterm infants with a gestational age of 26 - 33 weeks. All infants were ventilated or receive respiratory support by nasal CPAP. Results: 104 infants were enrolled, 49 in the vibration group and 55 in the control group. Demographic characters were in the vibration group compared to control group mean birth weight 1274 (± 335) gram vs. 1240 (± 351) gram and mean gestational age 29.8 (± 1.3) weeks vs. 29.9 (± 1.4) weeks. Vibration therapy did not reduce ventilation time (100 vs. 80 hours, p = 0.88) however duration of CPAP decreases significant (57 vs 157 hours, p < 0.018). Conclusion: Vibration therapy reduced Mean Airway Pressure, oxygen requirements and CPAP need in preterm infants, but did not reduce the duration of mechanical ventilation