Biomedical subjects

J van Limbeek

Publications and source records attributed to J van Limbeek.

At least 19 recordsLinked to original sources

PubMed2005

The Stroke Unit Discharge Guideline, a prognostic framework for the discharge outcome from the hospital stroke unit. A prospective cohort study.

OBJECTIVE: To investigate which factors during the subacute phase post stroke have predictive value for the discharge outcome from the hospital stroke unit. METHODS: In a prospective cohort of 338 patients admitted to a hospital stroke unit 26 potentially prognostic factors, arranged in clinical and social subdomains, were scored and analysed by binary logistic regression analysis. The outcome of the research consisted of the various discharge destinations. RESULTS: The overall predictive value of the discharge model is high (91%). Factors predictive of a poor discharge outcome are a low Barthel Index score (odds ratio (OR) 0.78 per point increase; p < 0.001), a poor sitting balance (OR 5.96; p < 0.001), a depression (OR 7.23; p < 0.001), poststroke cognitive disability (OR 3.51; p = 0.007) and older age (OR 1.05 per point increase; p = 0.008). If present, a personality disorder, premorbid cognitive disability and premorbid functional disability all show a tendency towards poor discharge outcome, but these factors did not reach statistical significance in this study, possibly due to their low prevalence. Readiness of the family circle to provide support was only significant in the univariate analysis. CONCLUSIONS: Somatic, biological and psychological factors predict the discharge outcome. Functional and cognitive factors play a decisive role in the future ability to live independently after a stroke. The prognostic importance of social factors could not be demonstrated. Urinary incontinence did not emerge as a prognostic factor. This is in contrast to scientific findings till now, but in accordance with clinical experience.

Age Factors↗

PubMed2004

Botulinum toxin effect on salivary flow rate in children with cerebral palsy.

OBJECTIVE: To investigate the effectiveness of botulinum neurotoxin (BoNT) type A in reducing salivary flow rate in children with cerebral palsy (CP) with severe drooling. METHODS: During a controlled clinical trial, single-dose BoNT injections into the submandibular salivary glands were compared with scopolamine treatment. Forty-five school-aged children were included. Salivary flow rates from all major glands were obtained at baseline and compared with measurements during the interventions. Basic statistics consisted of analysis of difference scores. RESULTS: Compared with baseline, the mean decrease in submandibular flow was 25% during scopolamine and 42% following BoNT injections. The difference scores were significant with maximum reductions 2, 4, and 8 weeks following BoNT. Of all children, 95% responded during scopolamine. Response rates for BoNT were significantly lower and varied from 69% at 2 weeks to 49% at 24 weeks after injection (the end of the study). Four patients discontinued scopolamine therapy because of side effects. Only incidentally mild side effects were reported from BoNT. CONCLUSIONS: Intraglandular BoNT injections significantly reduce salivary flow rate in the majority of drooling CP children, demonstrating high response rates up to 24 weeks. The procedure is simple to perform, effective, and safe when ultrasound guidance is used. The anticholinergic effect of BoNT exceeds that of scopolamine. As anticholinergic drugs are frequently contraindicated because of side effects, BoNT injections offer an alternative in the treatment of drooling.

Adolescent↗

PubMed2003

A systematic review for evidence of efficacy of anticholinergic drugs to treat drooling.

Drooling frequently occurs in children with multiple handicaps; application of anticholinergic drugs is a potential strategy to treat drooling. A computer aided search of original studies concerning the treatment of drooling was carried out. The methodological and statistical integrity of the identified studies were assessed with previously defined criteria. The articles were weighed for their separate contribution to the evidence. The search resulted in 64 reports, of which seven studies passed the screening and were subjected to further assessment and discussion by three referees. Because of the small number of reports and the methodological restriction within the studies, no meta-analysis could be performed. No general conclusion could be made about the efficacy of anticholinergic drugs in treatment of drooling in children with multiple handicaps. There was some evidence that three anticholinergic drugs (benztropine, glycopyrrolate, and benzhexol hydrochloride) are effective in the treatment of drooling, but it could not be concluded that one drug is preferable.

Child↗

PubMed2003

Prognostic factors for ambulation and activities of daily living in the subacute phase after stroke. A systematic review of the literature.

OBJECTIVE: To identify evidence-based prognostic factors in the subacute phase after stroke for activities of daily living (ADL) and ambulation at six months to one year after stroke. DESIGN: Systematic literature search designed in accordance with the Cochrane Collaboration criteria with the following data sources: (1) MEDLINE, EMBASE, CINAHL, Current Contents, Cochrane Database of Systematic Reviews, Psyclit, and Sociological Abstracts. (2) Reference lists, personal archives, and consultation of experts. (3) Guidelines. METHODS: Inclusion criteria were: (1) cohort studies of patients with an ischaemic or haemorrhagic stroke; (2) inception cohort with assessment of prognostic factors within the first two weeks after stroke; (3) outcome measures for ADL and ambulation; and (4) a follow-up of six months to one year. Internal, statistical and external validity of the studies were assessed using a checklist with 11 methodological criteria in accordance with the recommendations of the Cochrane Collaboration. RESULTS: From 1,027 potentially relevant studies 26 studies involving a total of 7,850 patients met the inclusion criteria. Incontinence for urine is the only prognostic factor identified in three studies with a level A (i.e., a good level of scientific evidence according to the methodological score). The following factors were found in one level A study: initial ADL disability and ambulation, high age, severe paresis or paralysis, impaired swallowing, ideomotor apraxia, ideational apraxia, and visuospatial construction problems; as well as factors relating to complications of an ischaemic stroke, such as extraparenchymal bleeding, cerebral oedema and size of intraparenchymal haemorrhage. CONCLUSIONS: The present evidence concerning possible predictors in the subacute stage of stroke has insufficient quality to make an evidence-based prediction of ADL and ambulation after stroke because only one prognostic factor was demonstrated in at least two level A studies, our cut-off for sufficient scientific evidence.

Activities of Daily Living↗

PubMed2003

Prognostic factors in the subacute phase after stroke for the future residence after six months to one year. A systematic review of the literature.

OBJECTIVE: To identify evidence-based prognostic factors in the subacute phase after a stroke for future residence at six months to one year post stroke. DESIGN: Systematic literature search designed in accordance with the Cochrane Collaboration criteria with the following data sources: (1) MEDLINE, EMBASE, CINAHL, Current Contents, Cochrane Database of Systematic Reviews, PsycLIT and Sociological Abstracts. (2) Reference lists, personal archives and consultation of experts in the field. (3) Guidelines. METHODS: Inclusion criteria were: (1) cohort studies of patients with an ischaemic or haemorrhagic stroke; (2) inception cohort with assessment of prognostic factors within the first two weeks after stroke; (3) outcome measures for future residence; and (4) a follow-up of six months to one year. Internal, statistical and external validity of the studies were assessed using a checklist with 11 methodological criteria in accordance with the recommendations of the Cochrane Collaboration. RESULTS: From 1027 potentially relevant studies 10 studies involving a total of 3564 patients met the inclusion criteria. No prognostic factor was identified in at least two level A (i.e., a good level of scientific evidence according to the methodological score) studies, our standard for scientific proof. The following factors were found in at least one level A study: low initial ADL functioning, high age, cognitive disturbance, paresis of arm and leg, not alert as initial level of consciousness, old hemiplegia, homonymous hemianopia, visual extinction, constructional apraxia, no transfer to the stroke unit, nonlacunar stroke type, visuospatial construction problems, urinary incontinence and female gender. CONCLUSIONS: At present there is insufficient evidence concerning possible predictors in the subacute stage of stroke to make an evidence-based prediction of the future residence. In the scientific research until now social factors and their contribution to the possibility of living independently have not been investigated, or at least less well. None of the studies in this review described a conceptual framework as basis for the choice of the examined prognostic factors.

Activities of Daily Living↗

PubMed2002

Treatment of upper extremity spasticity in stroke patients by focal neuronal or neuromuscular blockade: a systematic review of the literature.

Studies published from January 1966 until October 2000 on the clinical effects of focal neuronal and neuromuscular blockade in post stroke upper limb spasticity were identified. Twelve studies were included and evaluated on 13 methodological criteria. Ten studies on Botulinum toxin type A (BTX-A) treatment were found (of which 4 were randomised controlled trials (RCTs) and 6 were uncontrolled observational studies) as well as one uncontrolled observational study on phenol blockade of the subscapular muscle and one on alcohol blockade of the musculocutaneus nerve. The homogeneity of the patient groups with regard to diagnosis and their comparability with regard to functional prognosis and other sources of bias were generally unsatisfactory. Only two RCTs met predetermined criteria of minimal validity. There is evidence of effectiveness of BTX-A treatment on reducing muscle tone (varying between 0.8 and 2.0 points on the modified Ashworth scale) and improving passive range of motion at all arm-hand levels in chronic stroke patients for approximately 3-4 months. There is also preliminary evidence of a synergistic effect of concomitant electrostimulation. Taking into account a critical maximum dose of 100 MU Botox" (300-500 MU Dysport) for preserving active finger flexion, BTX-A treatment seems to be a safe focal spasmolytic treatment. Effectiveness of BTX-A treatment on improving functional abilities could not be convincingly demonstrated, although two subgroups may be identified that might specifically benefit at a functional level: (1) patients with mild spasticity and a potential for voluntary extensor activity and (2) patients with severe spasticity suffering from problems with positioning and taking care of the affected arm and hand. Larger controlled studies are needed to compare the effectiveness of BTX-A with other focal spasmolytic techniques paying special attention to individual goal assessment, the (duration of) functional benefits, co-treatment and aftercare, side-effects and cost-effectiveness.

Botulinum Toxins↗

PubMed2001

Is there a relation between neuropsychologic variables and quality of life after stroke?

OBJECTIVES: To describe the quality of life (QOL) of stroke patients and to distill neuropsychologic predictors for poor QOL. DESIGN: A cohort study in which patients were neuropsychologically assessed at a mean of 72.2 days after stroke, with follow-up at a mean of 9.8 months after stroke. SETTING: Research department of a rehabilitation center. PATIENTS: A consecutive sample of 164 stroke patients (mean age, 55.2yr) recruited from a university hospital, a regional hospital, and a rehabilitation center. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Orientation, memory, attention and concentration, visuospatial and visuoconstructive functions, language, and arithmetic skills were assessed with neuropsychologic tests. QOL was assessed with the Sickness Impact Profile (SIP). RESULTS: An overall mean SIP score +/- standard deviation of 20 +/- 11 showed that stroke has a high impact on everyday functioning. Further analyses indicated that QOL is related in particular to tests measuring spatiotemporal and/or sequential aspects of behavior. Forward/backward stepwise regression analysis (n = 106) showed that poor QOL was more likely if patients had a poor result on the Trailmaking Test (TMT) B and/or were women. CONCLUSION: The predictive value of the TMT is most effective and very useful because the TMT is a short and economical procedure. However, the gender-related aspects of recovery deserve more attention, as does the possible bias that can be caused by the composition of a measurement. Further research is needed to refine predictive models that are needed to facilitate the development of more adequate, individual rehabilitation programs.

Adolescent↗

PubMed2001

Urinary incontinence in stroke patients after admission to a postacute inpatient rehabilitation program.

OBJECTIVE: To determine the incidence of poststroke urinary incontinence in stroke patients admitted for a postacute inpatient rehabilitation program and its association with discharge destination. DESIGN: Cohort study of first-time stroke patients admitted for a postacute inpatient rehabilitation program from August 1994 to August 1997. SETTING: Rehabilitation center in the Netherlands. PARTICIPANTS: Consecutive first-time stroke patients (n = 143). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Incidence rates calculated with observation time at risk in the denominator. Measures for outcome include the Modified Barthel Index (MBI) and the discharge destination. RESULTS: The incidence rate of urinary incontinence was 29/1000 persons per month (95% confidence interval [CI], 18-48/1000 persons monthly). For incontinent patients, the mean initial MBI score +/- standard deviation was 6.0 +/- 2.3 (range, 2-12); for continent patients, it was 11.5 +/- 9.8 (range, 2-18). This difference was statistically significant (t(139) = 2.12; p = .036; 95% CI for difference of the means, .379-10.84). Patients continent at time of discharge were more often discharged to their own homes than were incontinent patients (Fisher's exact test, p = .0006). CONCLUSIONS: In this select cohort, the incidence of urinary incontinence was lower than that reported in the literature. An association was found between urinary incontinence and discharge destination and between urinary incontinence and functional ability on admission.

Adult↗

PubMed2001

Results with the M. E. Müller cemented, straight-stem total hip prosthesis: a 10-year historical cohort study in 180 women.

In 1986, 242 M. E. Muller (MEM) cemented, straight-stem total hip arthroplasty prostheses were implanted in 229 patients; 15 hips (13 patients) were lost to follow-up. Of the remaining 227 implants, 180 were placed in women, and 47 were placed in men (each with mean age, 71 +/- 7.7 years). After 10 years, 66 patients had died, and 152 implants were still in situ. As a result of aseptic loosening, 9 hips were revised (5 femoral and 4 acetabular components); two of these patients had a Girdlestone as a result of postoperative infection. Because 50% of the men died during follow-up, further analysis was performed with the 180 implants in women. The incidence of revision for aseptic loosening was 5.9 per 1,000 implants. The cumulative survival rate after 10 years was 94%. Survival was not influenced significantly by age, indication for operation, or having a contralateral hip prosthesis. The 10-year follow-up results for the MEM straight-stem total hip prosthesis in our hospital are satisfactory despite the probability that the cement mantle produced with this stem is not uniform in thickness.

Aged↗

PubMed2000

A systematic literature review to identify the best method for a single level anterior cervical interbody fusion.

The goal of this systematic literature review was to determine, for patients with degenerative disc disease, which method of single-level anterior cervical interbody fusion using the anterior approach gives the best clinical and radiological outcome. The number of new techniques for obtaining a solid fusion has increased rapidly, but the rationale for choosing between different techniques is unclear. Randomised comparative studies on anterior cervical interbody fusions were identified in a sensitive Medline, Cochrane and Current Contents database search. Two independent reviewers evaluated the articles that met the selection criteria, using a checklist. The search yielded eight randomised, controlled trials for the systematic literature review. Three of these studies were judged to be of sufficient quality with regard to methodology and the information provided. In the three articles, five different treatment methods were investigated, four of which were interbody fusions. Fusion rates varied between 28% for an allograft method and 63% for a discectomy-alone method. In one study, kyphosis varied from 40% to 62% between treatments. Good clinical outcome (disability, pain and symptoms) ratings varied from 66% to 82%. A meta-analysis to determine the best method for an anterior interbody fusion could not be performed due to the heterogeneity of the methods reported and because no standard outcome parameter was used. From this systematic literature review, a gold standard for the treatment of degenerative disc disease could not be identified.

Cervical Vertebrae↗

PubMed2000

Anterior lumbar interbody fusion with threaded fusion cages and autologous bone grafts.

The goal of this study was to evaluate the ability of Ray threaded fusion cages, when used in an anterior approach, to restore intervertebral height and to improve the functional and occupational performance of the patients. The present study was initiated because insertion of fusion cages through a posterior approach causes destruction of facet joints and violation of the spinal canal. The anterior approach for insertion of threaded fusion cages to accomplish lumbar interbody fusion was evaluated in a series of 13 patients suffering monosegmental disc disease. The patients' functional and occupational performance was evaluated using the Prolo score. Radiological measurements were used to evaluate disc height and degree of penetration into the endplates, and to confirm fusion. Seven of the 13 patients were short-term failures and had to be revised within 2 years. The study found that revised patients had poorer Prolo scores than non-revised patients. Although for the non-revised patients, the mean Prolo scores remained relatively stable during the 1st year, they dropped after 3 years. We were not able to identify any further clinical or radiological differences between the groups. These results indicate that although the anterior approach seems technically suitable for insertion of threaded fusion cages, destruction of the anterior longitudinal ligament and the anterior part of the annulus fibrosis appears to result in destabilisation of the motion segment.

Adult↗

PubMed2000

Itching after intrathecal morphine. Incidence and treatment.

This study was designed to determine whether low doses of intrathecal morphine still result in itching and it evaluates the outcome of a standardized treatment using promethazine and - for intractable itch - naloxone. Patients (n = 143) scheduled for total hip surgery were allocated to four groups (in a double blind manner) with bupivacaine 20 mg in 4 mL but different doses of intrathecal morphine: Group I, 0.025 mg, Group II, 0.05 mg, Group III, 0.1 mg and Group IV, 0.2 mg. The presence or absence of itching was noted every three hours for a 24-h period. When required, standardized treatment was provided. The incidence of itching was: Group I: 14. 3%; Group II: 21.6%; Group III: 48.6%; and, Group IV: 61.7%. Itch was treated by administering promethazine intramuscularly in 2.9% (Group I); 8.1% (Group II); 10.8% (Group III), and 8.9% (Group IV), respectively. Only in group IV there was a single patient who needed naloxone to treat itching. The incidence and severity of itching is a dose-related side-effect in the dose range of 0.025-0.2 mg of intrathecal morphine. Itching still occurs after the low doses of intrathecal morphine, but symptoms vanish after promethazine 25 mg intramuscularly.

Aged↗

PubMed2000

Kinematic assessment of manual skill following functional hand surgery in tetraplegia.

To determine whether surgical key grip reinforcement actually leads to a better movement ability we developed a procedure for the kinematic analysis of manual skill following hand surgery in tetraplegia. The functional results of surgery in 5 cases were examined by the kinematic analysis of drawing movements using an electronic pen and a digitizer under 3 conditions: with eyes open, with eyes closed, and while performing a concurrent arithmetic task. Movement velocity and dysfluency (ie, the number of velocity changes per centimeter) were measured before and at several moments after surgery during subsequent rehabilitation. Both movement velocity and dysfluency showed good stability across repeated trials and were consistently affected by visual deprivation. Movement velocity showed a 39% increment between the first and last assessment. Although grip strength increased in all patients, it was not associated with the change of movement velocity. These results suggest that other factors (eg, deep sensibility, cognition, muscle coordination) play a critical role in the ability to use improved grip force for controlling drawing movements and emphasize the value of a kinematic assessment besides measuring isolated grip force in the evaluation of functional hand surgery.

Adult↗

PubMed2000

Systematic review of aetiology and treatment of post-stroke hand oedema and shoulder-hand syndrome.

Studies on the aetiology and treatment of post-stroke hand oedema and shoulder-hand syndrome (SHS) published from January 1973 until August 1998 were identified. Eleven studies were included with at least some control for confounding. These were evaluated on 11 methodological criteria and by standardized effect sizes. There were five aetiological studies: four cohort studies and one study consisting of two case series using a within-subjects design. The matters investigated included lymph scintigraphy in hand oedema, bone scintigraphy, putative risk factors and the existence of autonomic dysregulation and peripheral nerve lesions in SHS. There were six therapeutic studies: one randomized controlled trial, one non-randomized controlled trial, one cohort study and three case series, of which two studies used a within-subjects design. These studies investigated continuous passive motion and neuromuscular stimulation in hand oedema as well as oral corticosteroids, intramuscular calcitonin and trauma prevention in SHS. A great diversity of pathophysiological and therapeutic insight was found. Based on systematic analysis of the literature, the following conclusions seem justified: (i) the shoulder is involved in only half of the cases with painful swelling of wrist and hand, suggesting a "wrist-hand syndrome" between simple hand oedema and SHS; (ii) hand oedema is not lymphoedema; (iii) SHS usually coincides with increased arterial blood flow; (iv) trauma causes aseptic joint inflammations in SHS; (v) no specific treatment has yet proven its advantage over other physical methods for reducing hand oedema; and (vi) oral corticosteroids are the most effective treatment for SHS.

Edema↗

PubMed2000

Effects of dialyser and dialysate on the acute phase reaction in clinical bicarbonate dialysis.

BACKGROUND: In chronic haemodialysis (HD), morbidity may result from repetitive induction of the acute phase response, caused by a bioincompatible dialysis membrane and/or contaminated dialysate. In the present study, cytokine release (interleukin-6, IL-6) and subsequent production of acute phase proteins (C-reactive protein, CRP and secretory phospholipase A(2), sPLA(2)) were assessed to investigate whether the HD-induced acute phase reaction depends mainly on the type of membrane or on the sterility of the dialysate. METHODS: In 11 patients, IL-6, CRP and sPLA(2) levels were assessed in blood samples drawn before (t(0)), at the end (t(180)) and 24 h after the start of HD (t(1440)). All patients were dialysed on Cuprammonium (CU) and Polysulphon (PS) dialysers and seven patients underwent an additional HD session on CU plus a dialysate filter (CUf). RESULTS: IL-6 levels were increased significantly at t(180) compared with t(0) (P<0.02) with both CU and CUf. At t(1440), IL-6 levels had returned to baseline. In contrast, marked fluctuations did not occur during HD with PS. At t(180), IL-6 was significantly greater with CU and CUf devices, than with PS (P<0.02). Following HD with CU and CUf, a significant increase in CRP was observed at t(1440), compared with postdialysis values (P</=0.05). In addition, sPLA(2) values were markedly increased at t(1440), compared with t(180), but only significant in the case of CU (P=0.01). IL-6 levels at t(180) were significantly correlated with CRP (r=0.50, P<0.01) and sPLA(2) (r=0.47, P=0.01) values at t(1440). During HD with PS membranes, neither CRP nor sPLA(2) values were markedly changed. CONCLUSIONS: In contrast to PS, both CU and CUf resulted in elevated IL-6 plasma levels at the end of HD, compared with t(0), which correlated with increased CRP and sPLA(2) values 24 h later. Therefore, the type of membrane, rather than the bacterial quality of the dialysate, seems to be responsible for the induction of the acute phase response during clinical bicarbonate HD.

Acute-Phase Reaction↗

PubMed2000

Hemodialysis-induced degranulation of polymorphonuclear cells: no correlation between membrane markers and degranulation products.

BACKGROUND/AIMS: Degranulation of polymorphonuclear leukocytes (PMN) during hemodialysis (HD) is usually assessed by measuring degranulation products. However, this process might also be estimated by the assessment of cell surface markers. In this study, the relationship between the expression of PMN degranulation markers (CD63 and CD66b) and the release of degranulation products [myeloperoxidase (MPO) and lactoferrin (LF)] was investigated during clinical HD in order to evaluate cell surface markers as a useful index of PMN degranulation. METHODS: The expression of CD63 and CD66b on PMN and the release of MPO and LF were investigated in 10 chronic HD patients, during both heparin (HDhep) and trisodium citrate anticoagulation (HDcit), in a randomized order. Samples were drawn from both the efferent and afferent lines of the dialyzer at 0, 7.5, and 180 min. RESULTS: During HDhep at first passage, a major increase in MPO (from 158 +/- 32 to 448 +/- 177 microg/l, p = 0.001) and LF (from 134 +/- 52 to 260 +/- 120 microg/l, p = 0.01) was found across the dialyzer, whereas marked changes were not observed during HDcit. The expression of CD63 and CD66b increased across the dialyzer during both anticoagulation modalities, but was only significant in the case of HDhep (CD63: mean fluorescence intensity from 247 +/- 61 to 331 +/- 118, p < 0.01; CD66b: mean fluorescence intensity from 340 +/- 76 to 434 +/- 103, p = 0.01). During HDhep a correlation was noted between the degranulation products and markers of both azurophilic and specific granules (MPO and CD63: r = 0.35; p < 0.01; LF and CD66b: r = 0.39, p < 0.01). Significant differences in the expression of CD63 and CD66b between HDhep and HDcit were not observed. When analyzing the combined data for both HDhep and HDcit, no correlation was observed between degranulation products and markers. CONCLUSION: Our data suggest that the measurements of cell surface markers may not be a reliable indicator of the degree of HD-induced PMN degranulation.

Adult↗

PubMed2000

A 'sufficient cause' model for dental caries.

BACKGROUND: It is generally believed that dental caries is an infectious disease. The occurrence of dental caries is affected by a variety of determinants. In order to estimate the precise extent of the relation between specific determinants and the outcome phenomenon (i.e. the occurrence of dental caries), a coherent disease model is required. This model should also permit multivariate analysis to control for confounders and interactions. Only with such a disease model will it be possible to investigate the relation between the occurrence of a determinant and dental caries, and to estimate the extent of this relation. The known causal models for the explanation of dental caries do not fully meet these requirements. METHOD: Rothman's 'sufficient cause' model has been used as a starting point for the development of a new coherent disease model, to explain the occurrence of dental caries and allow multivariate analysis. RESULTS: The sufficient cause for dental caries comprises three component causes: sufficient microorganisms with cariogenic potential, easily fermentable carbohydrates and teeth. Whether dental caries actually occurs also depends on the influence of independent risk factors that interact with the component causes in a protective, as well as in a risk-increasing manner. These independent risk factors are saliva, fluoride, oral hygiene and diet. CONCLUSIONS: The 'sufficient cause' model for dental caries is a biological model in which distinction between protective and risk-increasing factors has been made, and interaction between factors has been described. With this model, it will now be possible to assess the extent of the relationship between a determinant and dental caries (the outcome phenomenon) using multivariate techniques.

Confounding Factors, Epidemiologic↗

PubMed1999

Temporary external transpedicular fixation of the lumbosacral spine.

STUDY DESIGN: In this study, 133 patients with incapacitating low back pain underwent temporary external transpedicular fixation of the lumbosacral spine in a prospective trial. Of these patients, 67% had undergone one or more spinal procedures in the past. On the basis of temporary external transpedicular fixation, 55 of 133 patients were treated conservatively. With an average follow-up period of 37 months, the clinical results were analyzed. OBJECTIVE: To evaluate temporary external transpedicular fixation as a test for selecting suitable candidates for fusion of the lumbosacral spine. SUMMARY OF BACKGROUND DATA: The few reports regarding this test are contradictory in terms of predictive value and morbidity. Only three reports include a placebo trial. METHODS: All patients were tested with the external fixator in three different positions: neutral fixation, slight distraction, and nonfixation (bars disconnected). The patient was unaware of the exact position of the external fixator and thus served as his or her own control. Before and during the test and at follow-up examination, pain was assessed on a visual analog scale. RESULTS: In the group that eventually underwent spinal fusion, the average preoperation visual analog scale score was 77. During test fixation, the average score was 26, in nonfixation 69, and at follow-up after surgery 40. In the control group, these figures were 75, 53, 44, and 71, respectively. As statistical analysis showed, the only factors that could be associated with the improved pain score was the performance of the spinal fusion (P = 0.0001) and the duration of low back pain before the test (P = 0.04). CONCLUSION: In selecting suitable candidates for spinal fusion, temporary external transpedicular fixation (including a placebo trial) can be a valuable test.

Adult↗