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Tolerance of suicide, religion and suicide rates: an ecological and individual study in 19 Western countries.

BACKGROUND: Negative associations between religion and suicide, in individuals and countries, may be mediated by the degree to which suicide is tolerated. METHODS: Linear regression was used to examine ecological associations between suicide tolerance, religion and suicide rates in 19 Western countries in 1989/90. Logistic regression was used to study associations between suicide tolerance and strength of religious belief in 28085 individuals in these countries. The concept of effect modifying function was used to examine whether the strength of the association between suicide tolerance and religious belief in individuals depended on the extent of religious belief in their country. RESULTS: Higher female suicide rates were associated with lower aggregate levels of religious belief and, less strongly, religious attendance. These associations were mostly attributable to the association between higher tolerance of suicide and higher suicide rates. In the 28085 subjects suicide tolerance and the strength of religious belief were negatively associated even after adjustment for other religious and sociodemographic variables and general tolerance levels (odds ratios: men 0.74 (95% CI 0.58-0.94), women 0.72 (95% CI 0.60-0.86)). This negative individual-level association was more pronounced in more highly religious countries but this modifying effect of the religious context was apparent for men only. CONCLUSIONS: Ecological associations between religious variables and suicide rates are stronger for women than men, stronger for measures of belief than observance and mediated by tolerance of suicide. In individuals, stronger religious beliefs are associated with lower tolerance of suicide. Personal religious beliefs and, for men, exposure to a religious environment, may protect against suicide by reducing its acceptability.

Adult↗

Detecting acute coronary syndrome in the emergency department with cardiac magnetic resonance imaging.

BACKGROUND: Managing chest pain in the emergency department remains a challenge with current diagnostic strategies. We hypothesized that cardiac MRI could accurately identify patients with possible or probable acute coronary syndrome. METHODS AND RESULTS: The diagnostic performance of MRI was evaluated in a prospective study of 161 consecutive patients. Enrollment required 30 minutes of chest pain compatible with myocardial ischemia but an ECG not diagnostic of acute myocardial infarction. MRI was performed at rest within 12 hours of presentation and included perfusion, left ventricular function, and gadolinium-enhanced myocardial infarction detection. MRI was interpreted qualitatively but also analyzed quantitatively. The sensitivity and specificity, respectively, for detecting acute coronary syndrome were 84% and 85% by MRI, 80% and 61% by an abnormal ECG, 16% and 95% for strict ECG criteria for ischemia (ST depression or T-wave inversion), 40% and 97% for peak troponin-I, and 48% and 85% for a TIMI risk score > or =3. The MRI was more sensitive than strict ECG criteria for ischemia (P<0.001), peak troponin-I (P<0.001), and the TIMI risk score (P=0.004), and MRI was more specific than an abnormal ECG (P<0.001). Multivariate logistic regression analysis showed MRI was the strongest predictor of acute coronary syndrome and added diagnostic value over clinical parameters (P<0.001). CONCLUSIONS: Resting cardiac MRI exhibited diagnostic operating characteristics suitable for triage of patients with chest pain in the emergency department. Performed urgently to evaluate chest pain, MRI accurately detected a high fraction of patients with acute coronary syndrome, including patients with enzyme-negative unstable angina.

Acute Disease↗

A bivariate functional mapping model for identifying haplotypes that control drug response for systolic and diastolic blood pressures.

A bivariate functional mapping model has been proposed to detect haplotype-based DNA sequence variants that regulate the response curves of systolic and diastolic blood pressures (SBP and DBP) to a particular drug. This model capitalizes on the haplotype structure constructed by single nucleotide polymorphisms (SNPs) and incorporates the mathematical aspects of pharmacodynamic reactions into the estimation process, aimed to identify DNA sequence variants responsible for drug response. In this way, by estimating and testing the curve parameters that define drug response, many genetically and clinically meaningful hypotheses regarding the degree and pattern of the genetic control of SBP and DBP can be formulated, tested and disseminated. In a pharmacogenetic study composed of 107 subjects, our bivariate model has probed two haplotypes within the beta 2AR candidate gene that exert a significant effect on both SBP and DBP respond to dobutamine. With this candidate gene, two SNPs are genotyped, with allele Gly16 (G) and Arg16 (A) at codon 16 and alleles Glu27 (G) and Gln27 (C) at codon 27, respectively. The significant haplotypes are [AC] for SBP and [GG] for DBP. This model provides a powerful tool for elucidating the genetic variants of drug response and ultimately designing personalized medications based on each patient's genetic makeup.

Algorithms↗

Geographic differences in species boundaries among members of the Montastraea annularis complex based on molecular and morphological markers.

The three members of the Montastraea annularis complex (M. annularis, M. franksi, and M. faveolata) are dominant reef builders in the western Atlantic whose species status has been controversial for over a decade. Although differences in colony morphology and reproductive characteristics exist, interspecific fertilizations are possible in the laboratory and genetic differentiation is slight. Here we compare the three taxa genetically and morphologically in Panama and the Bahamas, widely separated locations spanning most of their geographic ranges. In Panama, analyses of three AFLP loci, a noncoding region of the mitochondrial genome, and ITS sequences reveal that M. faveolata is strongly differentiated genetically. Discriminant function analysis also indicates no overlap with the other two species in the fine structure of the corallites that comprise the colony. Genetic analyses of larvae from interspecific crosses between M. faveolata and the other two taxa confirmed the hybrid status of the larvae, but no examples of the most probable F1 genotype were observed in the field. Although M. annularis and M. franksi were more similar, they also exhibited strong frequency differences at two AFLP loci and in the mitochondrial noncoding region, as well as distinct corallite structure. In the Bahamas, in contrast, the three taxa exhibited overlapping morphologies. Montastraeafranksi and M. annularis were indistinguishable genetically, and M. faveolata was distinct at fewer genetic loci. Once again, however, the most probable F1 genotype involving M. faveolata was not observed. Geographic differences between Panama and the Bahamas explain why past studies have come to different conclusions concerning the status of the three species. In general, the genetic and morphological data suggest a north to south hybridization gradient, with evidence for introgression strongest in the north. However, reproductive data show no such trend, with intrinsic barriers to gene flow comparable or stronger in the north.

Animals↗

Evaluation of objective functions for estimation of kinetic parameters.

There is growing interest in quantitatively analyzing in vivo image data, as this facilitates objective comparisons and measurement of effect. In this regard, people increasingly turn to pharmacokinetic models and estimation of parameters of such models. In this work several parameter estimation methodologies were compared within the context of the most common pharmacokinetic model used in positron emission tomography imaging to describe glucose metabolism and receptor-ligand interactions at tracer concentrations. Simulated data were generated with 1000 realizations at each of 5 different noise levels. Estimates of the kinetic parameters were made for each realization using seven iterative, nonlinear estimation methodologies: ordinary least squares (OLS), weighted least squares (WLS), penalized weighted least squares (PWLS), iteratively reweighted least squares (IRLS), and variations of extended least squares (ELS0, ELS1, ELS3). Additionally, generalized linear least squares (GLLS) was also used. With relatively noise-free data, the iterative nonlinear estimation methods generally produced low-bias, high-precision parameter estimates, whereas with GLLS the bias was more prominent. Greater distinction between the estimation methods was seen at the higher, more realistic noise levels, with ELS and IRLS methods generally achieving better precision than the other methods. At the high noise levels WLS, GLLS, and PWLS yielded parameter estimates with large bias (>200%) for some kinetic parameters. In general, there are more favorable estimator methodologies than the frequently employed WLS. Methods that determine values of weights based on model output--IRLS, ELS0, ELS1 and ELS3--generally perform better than methods that determine values of weights based directly on the experimental data.

Analysis of Variance↗

Using missing data techniques to explore the lack of survival effect: illustration with the CABG patch trial.

The Multicenter Automatic Defibrillator Implantation Trial (MADIT) showed a conclusive 54 per cent reduction in mortality in patients with inducible sustained monomorphic ventricular tachycardia (VT) and impaired left ventricular function who received an implantable defibrillator compared with those who did not. The Coronary Artery Bypass Graft (CABG) Patch Trial, which studied a patient population with a similar extent of left ventricular dysfunction and overall cardiovascular risk, demonstrated no mortality benefit from placement of an implantable defibrillator. All patients in the MADIT trial were 'VT inducible', while this criterion was neither required nor evaluated for entry into the CABG Patch Trial. A statistical approach to estimating with good accuracy the fraction of CABG Patch patients who were inducible at the time of their randomization from the prevalence of VT inducibility in the surviving CABG Patch Trial control population during follow-up is presented. This more generally applicable approach estimates the mixing percentage using missing data techniques. We present the mathematical and physiological basis of the assumptions underpinning the mixture model and its estimation procedure. The mixture model forms the basis for the electrophysiological substudy to the CABG Patch Trial, which directly tests the hypothesis that the difference in the frequency of inducible VT between the MADIT and CABG Patch patients populations is sufficient to account for the difference in effect on mortality.

Algorithms↗

Phylogenetic position of Salinibacter ruber based on concatenated protein alignments.

A total of 22 genes from the genome of Salinibacter ruber strain M31 were selected in order to study the phylogenetic position of this species based on protein alignments. The selection of the genes was based on their essential function for the organism, dispersion within the genome, and sufficient informative length of the final alignment. For each gene, an individual phylogenetic analysis was performed and compared with the resulting tree based on the concatenation of the 22 genes, which rendered a single alignment of 10,757 homologous positions. In addition to the manually chosen genes, an automatically selected data set of 74 orthologous genes was used to reconstruct a tree based on 17,149 homologous positions. Although single genes supported different topologies, the tree topology of both concatenated data sets was shown to be identical to that previously observed based on small subunit (SSU) rRNA gene analysis, in which S. ruber was placed together with Bacteroidetes. In both concatenated data sets the bootstrap was very high, but an analysis with a gradually lower number of genes indicated that the bootstrap was greatly reduced with less than 12 genes. The results indicate that tree reconstructions based on concatenating large numbers of protein coding genes seem to produce tree topologies with similar resolution to that of the single 16S rRNA gene trees. For classification purposes, 16S rRNA gene analysis may remain as the most pragmatic approach to infer genealogic relationships.

Algorithms↗

Rapid electrostatic evolution at the binding site for cytochrome c on cytochrome c oxidase in anthropoid primates.

Cytochrome c (CYC) oxidase (COX), a multisubunit enzyme that functions in mitochondrial aerobic energy production, catalyzes the transfer of electrons from CYC to oxygen and participates in creating the electrochemical gradient used for ATP synthesis. Modeling three-dimensional structural data on COX and CYC reveals that 57 of the >1,500 COX residues can be implicated in binding CYC. Because of the functional importance of the transfer of electrons to oxygen, it might be expected that natural selection would drastically constrain amino acid replacement rates of CYC and COX. Instead, in anthropoid primates, although not in other mammals, CYC and COX show markedly accelerated amino acid replacement rates, with the COX acceleration being much greater at the positions that bind CYC than at those that do not. Specifically, in the anthropoid lineage descending from the last common ancestor of haplorhines (tarsiers and anthropoids) to that of anthropoids (New World monkeys and catarrhines) and that of catarrhines (Old World monkeys and apes, including humans), a minimum of 27 of the 57 COX amino acid residues that bind CYC were replaced, most frequently from electrostatically charged to noncharged residues. Of the COX charge-bearing residues involved in binding CYC, half (11 of 22) have been replaced with uncharged residues. CYC residues that interact with COX residues also frequently changed, but only two of the CYC changes altered charge. We suggest that reducing the electrostatic interaction between COX and CYC was part of the adaptive evolution underlying the emergence of anthropoid primates.

Adaptation, Physiological↗

Radiographic resolution of community-acquired bacterial pneumonia in the elderly.

OBJECTIVES: To investigate the radiographic clearance of proven community-acquired nontuberculous bacterial pneumonia in nonimmunocompromised older patients to provide working estimates of the rate of radiographic resolution as a function of the patient cumulative comorbidities, extent of initial radiographic involvement, functional status, and causative pathogens. DESIGN: A prospective study. PARTICIPANTS: Seventy-four patients aged 70 and older, consecutively admitted to a hospital for community-acquired bacterial pneumonia. SETTING: A university-affiliated teaching hospital. MEASUREMENTS: Chest radiographs were performed every 3 weeks from the date of admission for a total period of 12 weeks or until all radiographic abnormalities had resolved or returned to baseline. RESULTS: Sixty-four patients (86%) completed the study. The rate of radiographic clearance was estimated at 35.1% within 3 weeks, 60.2% within 6 weeks, and 84.2% within 12 weeks. Radiographic resolution was significantly slower for those with high comorbidity index, bacteremia, multilobar involvement, and enteric gram-negative bacilli pneumonias. Multivariate regression analysis demonstrated that the comorbidity index (relative risk for clearance=0.67 per class index, P<.001) and multilobar disease (relative risk for clearance=0.24 for more than one lobe, P<.001) had independent predictive value (Cox proportional hazards regression model) on the rate of resolution. CONCLUSION: The radiographic resolution of nontuberculous bacterial pneumonia in the elderly should take into account the extent of lobar disease and the burden of underlying illnesses. A waiting period of 12 to 14 weeks is recommended for slowly resolving pneumonia to be considered nonresolving.

Aged↗

Executive function in first-episode schizophrenia.

BACKGROUND: We tested the hypothesis that schizophrenia is primarily a frontostriatal disorder by examining executive function in first-episode patients. Previous studies have shown either equal decrements in many cognitive domains or specific deficits in memory. Such studies have grouped test results or have used few executive measures, thus, possibly losing information. We, therefore, measured a range of executive ability with tests known to be sensitive to frontal lobe function. METHODS: Thirty first-episode schizophrenic patients and 30 normal volunteers, matched for age and NART IQ, were tested on computerized test of planning, spatial working memory and attentional set shifting from the Cambridge Automated Neuropsychological Test Battery. Computerized and traditional tests of memory were also administered for comparison. RESULTS: Patients were worse on all tests but the profile was non-uniform. A componential analysis indicated that the patients were characterized by a poor ability to think ahead and organize responses but an intact ability to switch attention and inhibit prepotent responses. Patients also demonstrated poor memory, especially for free recall of a story and associate learning of unrelated word pairs. CONCLUSIONS: In contradistinction to previous studies, schizophrenic patients do have profound executive impairments at the beginning of the illness. However, these concern planning and strategy use rather than attentional set shifting, which is generally unimpaired. Previous findings in more chronic patients, of severe attentional set shifting impairment, suggest that executive cognitive deficits are progressive during the course of schizophrenia. The finding of severe mnemonic impairment at first episode suggests that cognitive deficits are not restricted to one cognitive domain.

Adolescent↗

Three-dimensional window analysis for detecting positive selection at structural regions of proteins.

Detection of natural selection operating at the amino acid sequence level is important in the study of molecular evolution. Single-site analysis and one-dimensional window analysis can be used to detect selection when the biological functions of amino acid sites are unknown. Single-site analysis is useful when selection operates more or less constantly over evolutionary time, but less so when selection operates temporarily. One-dimensional window analysis is more sensitive than single-site analysis when the functions of amino acid sites in close proximity in the linear sequence are similar, although this is not always the case. Here I present a three-dimensional window analysis method for detecting selection given the three-dimensional structure of the protein of interest. In the three-dimensional structure, the window is defined as the sphere centered on the alpha-carbon of an amino acid site. The window size is the radius of the sphere. The sites whose alpha-carbons are included in the window are grouped for the neutrality test. The window is moved within the three-dimensional structure by sequentially moving the central site along the primary amino acid sequence. To detect positive selection, it may also be useful to group the surface-exposed sites in the window separately. Three-dimensional window analysis appears not only to be more sensitive than single-site analysis and one-dimensional window analysis but also to provide similar specificity for inferring positive selection in the analyses of the hemagglutinin and neuraminidase genes of human influenza A viruses. This method, however, may fail to detect selection when it operates only on a particular site, in which case single-site analysis may be preferred, although a large number of sequences is required.

Amino Acid Substitution↗

A comparison of population and standard two-stage pharmacokinetic analyses of vigabatrin data.

Vigabatrin (VGB), an irreversible inhibitor of GABA, is being developed as an add-on therapy for uncontrolled complex partial seizure. A single-dose study was conducted in three groups of subjects with normal, mild-to-moderate, and moderate-to-severe renal impairment to examine the effect of renal function on the pharmacokinetics of VGB. Serial blood samples were collected up to 60 h following a single 750 mg oral dose of VGB for the quantitation of drug concentrations. The plasma VGB concentration-time data were analyzed by mixed-effects modeling to estimate population pharmacokinetic parameters and to identify any significant demographic covariates. The parameters of VGB were also calculated by standard two-stage techniques and then compared to the results obtained using the mixed-effects analysis. Population VGB plasma concentration-time profiles were best described by a two-compartment model with zero-order absorption. Creatinine clearance was observed to significantly affect the oral clearance of VGB (p < 0.05), i.e. a linear increasing relationship existed between the two variables. Other demographic factors had no influence on VGB pharmacokinetics. There were agreements in the oral clearance, apparent volume of distribution during elimination, and half-life estimates calculated by both methods. In addition, the conventional technique identified a linear relationship between oral and creatinine clearances. In summary, mixed-effects modeling of serial vigabatrin data validated results determined by the standard two-stage technique.

4-Aminobutyrate Transaminase↗

Genetic effects on variation in red-blood-cell folate in adults: implications for the familial aggregation of neural tube defects.

Recent studies have implicated folic acid as an important determinant of normal human growth, development, and function. Insufficient folate levels appear to be a risk factor for neural tube defects (NTD), as well as for several chronic diseases of adulthood. However, relatively little is known about the factors that influence folate status in the general population. To estimate the relative contribution of genetic and nongenetic factors to variation in folate, we have evaluated red blood cell (RBC) folate levels in 440 pairs of MZ twins and in 331 pairs of DZ twins. The data were best described by a model in which 46% of the variance in RBC folate was attributable to additive genetic effects, 16% of the variance was due to measured phenotypic covariates, and 38% of the variance was due to random environmental effects. Moreover, the correlations for RBC folate in MZ co-twins (r = .46) and in repeat measures from the same individual (r = .51) were very similar, indicating that virtually all repeatable variation in RBC folate is attributable to genetic factors. On the basis of these results, it would seem reasonable to initiate a search for the specific genes that influence RBC folate levels in the general population. Such genes ultimately may be used to identify individuals at increased risk for NTD and other folate-related diseases.

Adult↗

Nuclear and nucleomorph SSU rDNA phylogeny in the Cryptophyta and the evolution of cryptophyte diversity.

The plastid-bearing members of the Cryptophyta contain two functional eukaryotic genomes of different phylogenetic origin, residing in the nucleus and in the nucleomorph, respectively. These widespread and diverse protists thus offer a unique opportunity to study the coevolution of two different eukaryotic genomes within one group of organisms. In this study, the SSU rRNA genes of both genomes were PCR-amplified with specific primers and phylogenetic analyses were performed on different data sets using different evolutionary models. The results show that the composition of the principal clades obtained from the phylogenetic analyses of both genes was largely congruent, but striking differences in evolutionary rates were observed. These affected the topologies of the nuclear and nucleomorph phylogenies differently, resulting in long-branch attraction artifacts when simple evolutionary models were applied. Deletion of long-branch taxa stabilized the internal branching order in both phylogenies and resulted in a completely resolved topology in the nucleomorph phylogeny. A comparison of the tree topologies derived from SSU rDNA sequences with characters previously used in cryptophyte systematics revealed that the biliprotein type was congruent, but the type of inner periplast component incongruent, with the molecular trees. The latter is indicative of a hidden cellular dimorphism (cells with two periplast types present in a single clonal strain) of presumably widespread occurrence throughout cryptophyte diversity, which, in consequence, has far-reaching implications for cryptophyte systematics as it is practiced today.

Cell Nucleus↗

A relative value method for measuring and evaluating cardiac reserve.

BACKGROUND: Although a very close relationship between the amplitude of the first heart sound (S1) and the cardiac contractility have been proven by previous studies, the absolute value of S1 can not be applied for evaluating cardiac contractility. However, we were able to devise some indicators with relative values for evaluating cardiac function. METHODS: Tests were carried out on a varied group of volunteers. Four indicators were devised: (1) the increase of the amplitude of the first heart sound after accomplishing different exercise workloads, with respect to the amplitude of the first heart sound (S1)recorded at rest was defined as cardiac contractility change trend (CCCT). When the subjects completed the entire designed exercise workload (7000 J), the resulting CCCT was defined as CCCT(1); when only 1/4 of the designed exercise workload was completed, the result was defined as CCCT(1/4). (2) The ratio of S1 amplitude to S2 amplitude (S1/S2). (3) The ratio of S1 amplitude at tricuspid valve auscultation area to that at mitral auscultation area T1/M1 (4) the ratio of diastolic to systolic duration (D/S). Data were expressed as mean +/- SD. RESULTS: CCCT(1/4) was 6.36 +/- 3.01 (n = 67), CCCT(1) was 10.36 +/- 4.2 (n = 33), S1/S2 was 1.89 +/- 0.94 (n = 140), T1/M1 was 1.44 +/- 0.99 (n = 144), and D/S was 1.68 +/- 0.27 (n = 172). CONCLUSIONS: Using indicators CCCT(1/4) and CCCT(1) may be beneficial for evaluating cardiac contractility and cardiac reserve mobilization level, S1/S2 for considering the factor for hypotension, T1/M1 for evaluating the right heart load, and D/S for evaluating diastolic cardiac blood perfusion time.

Adolescent↗

Use of item response theory to develop a shortened version of the EORTC QLQ-C30 emotional functioning scale.

BACKGROUND: As part of a larger study whose objective is to develop an abbreviated version of the EORTC QLQ-C30 suitable for research in palliative care, analyses were conducted to determine the feasibility of generating a shorter version of the 4-item emotional functioning (EF) scale that could be scored in the original metric. METHODS: We used data from 24 European cancer studies conducted in 10 different languages (n = 8242). Item selection was based on analyses by item response theory (IRT). Based on the IRT results, a simple scoring algorithm was developed to predict the original 4-item EF sum scale score from a reduced number of items. RESULTS: Both a 3-item and a 2-item version (item 21 'Did you feel tense?' and item 24 'Did you feel depressed?') predicted the total score with excellent agreement and very little bias. In group comparisons, the 2-item scale led to the same conclusions as those based on the original 4-item scale with little or no loss of measurement efficiency. CONCLUSION: Although these results are promising, confirmatory studies are needed based on independent samples. If such additional studies yield comparable results, incorporation of the 2-item EF scale in an abbreviated version of the QLQ-C30 for use in palliative care research settings would be justified. The analyses reported here demonstrate the usefulness of the IRT-based methodology for shortening questionnaire scales.

Adult↗

Potential novel predictors of mortality in end-stage renal disease patients with sleep disorders.

Patients with end-stage renal disease (ESRD) have an annual mortality rate exceeding 20%, although some survive many years. The ESRD population has a high incidence of sleep disorders, including sleep apnea and periodic limb movements in sleep (PLMS). Sleep disorders result in sleep deprivation, which can negatively affect immune function and cardiovascular-related outcomes, common causes of death in patients with ESRD. This study examined predictors of mortality in patients with ESRD with sleep problems. Twenty-nine consecutive patients with ESRD reporting disrupted sleep or daytime sleepiness were studied by all-night polysomnography. All patients were followed up until death, transplantation, or study termination. Among the variables studied, including such previously reported predictors as serum albumin level, urea reduction ratio, and hematocrit, only the PLMS index (PLMSI), arousing PLMSI (APLMSI), and total number of arousals per hour of sleep significantly predicted mortality. The 20-month survival rate with a PLMSI less than 20 was greater than 90% versus 50% for a PLMSI of 20 or greater (exact log-rank, P = 0.007). For the deceased versus survivor groups, mean PLMSI was 119.1 versus 19.8 (P = 0.01) and APLMSI was 48.1 versus 7.8 (P = 0.00006), with a mean survival of 10.3 versus greater than 25.5 months, respectively (P = 0.001). Median survival of patients with a PLMSI greater than 80 was only 6 months. PLMSI, APLMSI, and total arousals per hour of sleep were strongly associated with mortality in patients with ESRD with sleep disorders independent of other factors and may be novel predictors of near-term mortality.

Aged↗

Predictions of restoration deterioration.

This study evaluated the application of a mixture model involving a Weibull distribution function to predict the median times for restorations of three dental restorative materials to achieve unsatisfactory rating scores for six clinical factors. The accuracy of the method was assessed graphically against the known actuarial long-term deterioration observations of 1813 amalgam, 1774 anterior resin composite and 474 glass polyalkenoate (ionomer) cement restorations, assessed over periods of up to 20, 18 and 14 years, respectively. Of the six clinical factors investigated (which included marginal fracture), only four had sufficient long-term unsatisfactory rating score data to enable their median times to be predicted. These predicted times were: for amalgam restorations, surface roughness 32.5 years and surface tarnishing 16.0 years; for resin composites, marginal staining 25.4 years and colour mismatch 14.2 years; and for glass polyalkenoate (ionomer) cements, marginal staining 17.6 years and colour mismatch 3.6 years. The known and predictive unsatisfactory rating score results were generally in close agreement. However, it was not possible to predict median times for unsatisfactory rating scores associated with very slowly deteriorating restoration factors. The actual replacement rates of the amalgam restorations were too low to obtain their median survival time. However, for the faster failing resin composites this time was 7.9 +/- 0.5 years, and for the glass polyalkenoate (ionomer) cements 2.2 +/- 0.2 years. The relationship of restoration deterioration to restoration replacement and dental health requires further analysis.

Actuarial Analysis↗