Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Uncertainty score”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed2005

Perceived sources of stress within a dental educational environment.

The aim of this study was to identify the perceived sources of stress among dental students, dental hygiene students, and dental technology students enrolled at Jordan University of Science and Technology (JUST). The modified dental environment stress questionnaire was administered to 183 students. The perceived stressors varied between major and year. Dental students gave high scores for examinations, reduced holidays, inadequate time for relaxation, fear of failure, completing clinical requirements, and differences in opinion between staff. Dental hygiene students gave the highest scores for uncertainty about the field of study as future career, examinations, inadequate clinical training and supervision, inadequate relaxation, and discrimination between students. Dental technology students also gave high scores for uncertainty about future career, examinations, approachability of the staff, inadequate relaxation, and completing requirements. Females are more stressed than males with regard to personal factors. Dental technology and/or dental hygiene students have significantly higher scores than dental students in 12 items. Students who reported their first choice of study was not their current field of study showed more stress concerning their future careers. The high scores reported for some stressors among students emphasize the need to address student's concerns.

Adult↗
PubMed2005

Adjusting insulin doses: from knowledge to decision.

The aim of this study was to analyze the absence of adjustment of insulin doses in type 1 diabetic patients with poorly controlled diabetes. Twenty-eight patients (HbA(1)c higher than 8.5% during the last 6 months, performing at least three capillary blood glucose determinations per day), completed a questionnaire on the degree of confidence in their own knowledge, the nature of their health beliefs, their fear of hypoglycemia, their own appreciation on how they adjust their insulin doses (subjective score). An analysis of their diabetes logbook provided an objective score of the adjustment of doses actually performed. The results show that the subjective and objective scores of adjustment were not significantly correlated. Further there was a significant negative correlation between the score of uncertainty on knowledge and the subjective score of adjustment of the insulin doses, but not with the objective score. There was a significant correlation between the score of positive health beliefs and the subjective score of adjustment of the insulin doses, but not with the objective score. No correlation was found between the score of fear of hypoglycemia and the subjective score of adjustment of the insulin doses. Correlation with the objective score was higher, but not significant. Actually, the fear of hypoglycemia was the most frequently given reason for not adjusting the insulin doses, when the question was asked to the patients with an open answer. This study illustrates the difference between thinking and doing. It also shows that the degree of confidence in one's own knowledge, the health beliefs, and the fear of hypoglycemia differently influence the perception that the patients have of their behavior, and what they really do.

Adolescent↗
PubMed2004

[The relationship of uncertainty, hope and quality of life in patients with breast cancer].

PURPOSE: The purpose of this study was to explore the relationship of uncertainty, hope and quality of life in patients with breast cancer. METHOD: The subjects of the study were 113 breast cancer patients treated at 3 university hospitals in Daegu and Busan from June 1 to September 30, 2003. Uncertainty was measured by the Mishel Uncertainty in Illness Scale (MUIS), Hope was measured by Nowotny's Hope Scale, and quality of life by Ro's Korean Quality of Life(QOL). Data was analyzed with the SPSS program by t-test, ANOVA, Spearman's rank correlation and Multiple Regression Analysis. RESULT: The scores of uncertainty were negatively correlated with hope and QOL(all p's<0.05). Uncertainty revealed that there was a negative correlation among subitems of hope such as confidence, relationship with others, possibility of future, and inner motivation(r=-.333, p=.000; r=-.230, p=.015; r=-.260, p=.006; r=-.291, p=.003). Uncertainty also showed a negative correlation among subitems of QOL such as emotional status, self esteem, and relationship with family(r=-.29, p=.004; r=-.326, p=.000; r=-.197, p=.044), whereas hope revealed a positive correlation among subitems of QOL such as emotional status, self esteem, relationship with neighbor, and relationship with family(r=.243, p=.011; r=.487, p=.000; r=.29, p=.001; r=.29, p=.001). The score of uncertainty was low in graduate school students and subjects using problem solving as a coping method. However, the score of hope was high in college students and subjects using a problem solving method, and the score of QOL was high in professionals. CONCLUSION: Based on the study results, breast cancer patients experienced living with uncertainty and maintaining hope. Thus the study's findings can be useful in directing a comprehensive nursing care plan to improve QOL of breast cancer patients.

Adult↗
PubMed1999

[Knowledge, beliefs and attitudes of inmates towards AIDS and HIV infection: a survey in a Marseille penitentiary center].

BACKGROUND: The objectives of our study were to evaluate knowledge, attitudes and beliefs of inmates toward HIV infection, and to compare them with those reported in the general population and according to injecting drug use. METHODS: Three hundred and seventy persons incarcerated in the prison of Marseille were invited, between December 1995 and March 1997, to answer a voluntary questionnaire offered by an independent staff. Odds ratios were estimated by logistic regression models adjusting for age, sex and type of questionnaire (self-administered for literate, face-to-face for illiterate inmates). The average scores among injecting and non injecting drug users (IDUs) were compared by analysis of variance adjusting for age, sex and type of questionnaire. These scores were also compared with those reported in a national survey (ACSF 1994), after adjustment for age, sex and educational level. RESULTS: The participation rate was 55%. Among the 202 participants, 152 answered a self-administered and 50 a face-to-face questionnaire; 45/202 (22%) were IDUs. The average scores of knowledge and tolerance towards HIV infected people were lower among inmates than in the general population. Furthermore, the scores of uncertainty towards HIV risk and unfavorable opinions about condom were higher than in the general population. While the average scores of knowledge, uncertainty towards HIV risk and unfavorable opinions did not differ between IDUs and non-IDUs, the score of tolerance towards HIV infected people was lower among non-IDUs than IDUs. CONCLUSION: That study shows that in spite of the high prevalence of at risk behaviors among people who are incarcerated, that population is not targeted enough by HIV prevention programs. Furthermore, the low level of tolerance towards HIV infected people among inmates, especially non-IDUs, is very likely an obstacle to health care management in that population with a high HIV prevalence. It is urgent to enhance the equality of access to care and prevention policy inside and outside prison.

Adult↗
PubMedDate not supplied

Personality and alcohol/substance-use disorder patient relapse and attendance at self-help group meetings.

This study evaluated the role of personality in the short-term outcome of alcohol/substance-use disorder patients. Detoxifying alcohol/substance-use disorder patients were administered the Myers-Briggs Type Indicator (MBTI), the Tridimensional Personality Questionnaire (TPQ), the Michigan Alcohol Screening Test (MAST), the CAGE Questionnaire, and the Beck Depression Inventory (BDI). These patients were subsequently evaluated over a 1-month period for relapse and attendance at self-help group meetings. High TPQ Persistence scale scores predicted abstinence. When the Thinking and Feeling groups were considered separately, and when these two groups were combined into a single group, high scores for the individual groups and the combined group (i.e. Thinking and Feeling types together) predicted abstinence. High TPQ Persistence scale scores and low Shyness with Strangers and Fear of Uncertainty subscale scores predicted attendance at self-help group meetings. High MBTI Extroversion and high MBTI Thinking scores also predicted attendance at self-help group meetings. When the Extroverted and Introverted types and the Thinking and Feeling types respectively were combined, as with abstinence, high scores predicted attendance at self-help group meetings. Age, gender, CAGE, MAST, and BDI scores did not predict outcome. The above information suggests that specific personality variables may predict abstinence and attendance at self-help group meetings in recently detoxified alcoholics, and this may have prognostic and therapeutic significance.

Adult↗
PubMed2004

New developments in automated cytogenetic imaging: unattended scoring of dicentric chromosomes, micronuclei, single cell gel electrophoresis, and fluorescence signals.

The quantification of DNA damage, both in vivo and in vitro, can be very time consuming, since large amounts of samples need to be scored. Additional uncertainties may arise due to the lack of documentation or by scoring biases. Image analysis automation is a possible strategy to cope with these difficulties and to generate a new quality of reproducibility. In this communication we collected some recent results obtained with the automated scanning platform Metafer, covering applications that are being used in radiation research, biological dosimetry, DNA repair research and environmental mutagenesis studies. We can show that the automated scoring for dicentric chromosomes, for micronuclei, and for Comet assay cells produce reliable and reproducible results, which prove the usability of automated scanning in the above mentioned research fields.

Animals↗
PubMed2000

Association of coping responses with fibromyalgia tender points in patients with systemic lupus erythematosus.

OBJECTIVE: To determine the association between fibromyalgia (FM) tender points (TP) and psychological constructs in patients with systemic lupus erythematosus (SLE). METHODS: One hundred seventy-three patients with SLE were examined for FM TP, and asked to complete 2 questionnaires at the same visit, the Health-Related Hardiness Scale (HRHS), and the Mishel Uncertainty in Illness Scale (MUIS). RESULTS: The examination of FM TP showed that 38.2% had no TP, 44.5% had 1-10 TP, and 17.3% had > or = 11 TP. The mean +/- SD score of the HRHS was 155.6 +/- 19.7 (range 105.0-198.0; higher scores indicate greater hardiness), and the MUIS was 85.3 +/- 18.7 (range 41.0-132.0; higher scores indicate uncertainty). There were significant associations between FM TP and HRHS (no TP 161.2 +/- 20.2, 1-10 TP 152.5 +/- 19.7, > or = 11 TP 151.0 +/- 15.8; p = 0.0108) and between FM TP and MUIS (no TP 78.2 +/- 20.2, 1-10 TP 86.9 +/- 17.6, > or = 11 TP 95.8 +/- 14.7; p = 0.0001). CONCLUSION: This study shows a strong association between FM TP and uncertainty or lack of "hardiness." We conclude that SLE patients with FM TP are less likely to be good "copers." Prospective studies to determine if "poor coping" predicts FM in SLE are recommended. If the association between coping and FM is causal, it will justify interventions to improve coping and similar constructs, such as self-efficacy.

Adaptation, Psychological↗
PubMed2001

An exploration of the relationships between uncertainty, psychological distress and type of coping strategy among Chinese men after cardiac catheterization.

The experience of cardiac catheterization (CC) has included feelings of uncertainty, stress, fear and anxiety in many patients. However, conflicting findings from previous research have been reported. Chinese patients who undergo CC may experience psychological distress in a different way to other cultures as a result of traditional beliefs. Moreover, little research examining the impact of CC among Hong Kong Chinese has been carried out. Therefore, the aim of the study was to explore relationships between uncertainty, psychological distress and coping strategy in Chinese men after CC, using Mishel's model of uncertainty in illness as a framework. A convenience sample of 27 men hospitalized for cardiac catheterization participated in this study using a descriptive, correlational research design. Ethical approval was obtained from the Ethics Committee of the Medical Faculty at the Chinese University of Hong Kong and from the Executive Committee of the hospital. Participation was on a voluntary basis with patient confidentiality assured. Self-report questionnaires included Chinese versions of Mishel's Uncertainty in Illness Scale (MUIS), the Profile of Mood States (POMS), the State-Trait Anxiety Inventory (STAI) and the Chinese Coping Scale (CCS) for data collection. Data were analysed using the Statistical Package for Social Sciences. High mean scores for uncertainty (mean=101.4, SD=11.49) and variables measuring psychological distress (mood disturbance mean=36.6, SD=33.6, state-anxiety mean=39.1, SD=8.95, trait-anxiety mean=43.7, SD=8.1) among these participants suggest that Hong Kong Chinese men experience uncertainty and psychological distress when undergoing cardiac catheterization. Strong relationships between uncertainty and mood disturbance (r=0.57, P=0.01), trait-anxiety and mood disturbance (r=0.65, P=0.01) and state-anxiety and external coping strategies (r=0.50, P=0.05) were found. These findings suggest that relationships between uncertainty, psychological distress and external coping strategies exist in Chinese men hospitalized for cardiac catheterization. Moreover, these findings may help nurses' design culturally specific interventions for their patients.

Adaptation, Psychological↗
PubMed2003

Impact of the analysis of a bone density reference range on determination of the T-score.

There are uncertainties concerning the optimal threshold value of bone mineral density (BMD) for the diagnosis of osteoporosis using dual-energy X-ray absorptiometry (DXA). The most widely accepted clinical criteria are based on T- and Z-scores, derived statistically from an age-dependent BMD reference range that includes healthy young adults. This study has compared different analyses of BMD data of healthy, nonfractured, adult white females aged 18-90 years, consisting of 953 studied with DXA in the L1-L4 spine and 1018 measured at the hip. Four regression curves were applied to each reference data set; mean peak BMD (PBMD(R)) and the age-independent standard deviation (SD(R)) were calculated. These data, plus derived T-score thresholds, were compared with equivalent values (PBMD(YN), SD(YN)) determined from BMDs of a subgroup of young normals. Choice of regression curve caused a variation of 0.044 g/cm(2) in spinal PBMD(R) and 0.015-0.022 g/cm(2) in the hip. The variation in calculated SD(R) between the regressions was minimal (maximum variation, 0.03 SD unit in the spine). A split-linear model was chosen as the best overall fit for both the spine and the hip on the basis of goodness-of-fit and biological plausibility. PBMD(R) and PBMD(YN) varied by less than 1% at the spine or hip. Although the difference between SD(R) and SD(YN) was < or =7% for the hip sites, SD(R) was 0.022 g/cm(2) > SD(YN) for the spine (17% difference). At each hip site, BMD T-score thresholds, derived from regression analysis of the entire reference range (T(R)) or from young normals only (T(YN)), were not significantly different; however, equivalent spinal values differed by 0.062 g/cm(2) for T = -2.5. The percentage of the Australian female population (AFP) aged 50 yr or older and classified as osteoporotic, using population census data and the split-line-based T-score threshold of T(R) = -2.5, was 23% for spinal BMD and 17% for the total hip. For T(YN) = -2.5, the values were 36% (spine) and 17% (total hip). The hip BMDs of this study were greater than those of NHANES III in the third, seventh and eighth decades by as much as 0.6 SD. This produced a difference of 0.049-0.077 g/cm(2) for T(YN) = -2.5 between the two reference ranges.

Absorptiometry, Photon↗
PubMed2005

A new method for identifying informative genetic markers in selectively bred rats.

Microsatellite length polymorphisms are useful for the mapping of heritable traits in rats. Over 4000 such microsatellites have been characterized for 48 inbred rat strains and used successfully to map phenotypes that differ between strains. At present, however, it is difficult to use this microsatellite database for mapping phenotypes in selectively bred rats of unknown genotype derived from outbred populations because it is not immediately obvious which markers might differ between strains and be informative. We predicted that markers represented by many alleles among the known inbred rat strains would also be most likely to differ between selectively bred strains derived from outbred populations. Here we describe the development and successful application of a new genotyping tool (HUMMER) that assigns "heterozygosity" (Het) and "uncertainty" (Unc) scores to each microsatellite marker that corresponds to its degree of heterozygosity among the 48 genotyped inbred strains. We tested the efficiency of HUMMER on two rat strains that were selectively bred from an outbred Sprague-Dawley stock for either high or low activity in the forced swim test (SwHi rats and SwLo rats, respectively). We found that the markers with high Het and Unc scores allowed the efficient selection of markers that differed between SwHi and SwLo rats, while markers with low Het and Unc scores typically identified markers that did not differ between strains. Thus, picking markers based on Het and Unc scores is a valuable method for identifying informative microsatellite markers in selectively bred rodent strains derived from outbred populations.

Animals↗
PubMed2005

Reconciling population benefits and women's individual autonomy in mammographic screening: in-depth interviews to explore women's views about 'informed choice'.

OBJECTIVE: To explore women's reactions to 'informed choice' in mammographic screening. SETTING AND METHODS: Telephone interviews with a convenience sample of 106 women aged 45-70 years recruited from general practices in Sydney. RESULTS: Many (42%) women preferred an active role in decision-making. Respondents had low scores for 'uncertainty' and 'factors contributing to uncertainty' in response to explicit questions about the decision to have mammographic screening. Yet respondents indicated significantly greater willingness to have a test when the benefit of a 'new' screening test for breast cancer was expressed as relative risk reduction (RRR) (88%) than either absolute risk reduction (ARR) (78%) (McNemar's test: chi(2)1=7.14, p=0.013) or all-cause mortality (53%) (McNemar's test: chi(2)1=35.1, p<0.01). Significantly more respondents considered information about ARR 'new' to them (65%) compared with RRR information (30%) (McNemar's test: chi(2)1=25.83, p<0.01). CONCLUSIONS: As mammographic screening exposes well women to potential harms for an overall population benefit, it is challenging to ensure 'informed choice'. Our results suggest women will likely appreciate individual consultations as the context in which to share complex information that women in our study agreed they need to know about mammographic screening. Our results also demonstrate that women's willingness as individuals to participate in mammographic screening is influenced by 'framing effect'. Hence, the quantitative content of decision aids to promote 'informed choice' must be comprehensive and balanced.

Aged↗
PubMed2004

Limitations of score-based daily outcome predictions in the individual intensive care patient. An example of the RIAHDH algorithm.

OBJECTIVE: The nature of score-based predictions is probabilistic, and their accuracy depends on the reliability and validity of the applied system. As an example, the present study investigates the accuracy of the RIP-algorithm (RIP = Riyadh Intensive Care Program) based on daily APACHE II scores, and compares it with published results of that algorithm from other investigators. DESIGN: Prospective observational study and review of the literature. PATIENTS AND METHODS: 1,986 consecutive admissions of 1,808 patients to a surgical intensive care unit were documented. Daily changes of score values were used to derive a risk of death estimation. Sensitivity and the rate of false predictions were calculated for score-based predictions. Health status one year after discharge was assessed in survivors predicted to die. RESULTS: Daily application of the algorithm identified 109 situations leading to death predictions in 56 patients. Five of these patients were discharged alive from the hospital (positive predictive value 91%). One year later 3 of these patients were still alive. The algorithm identified 51 of the non-survivors (sensitivity 19%), 110 died in the ICU without prediction. Altogether 270 patients died during their hospital stay. Among the 6 independent validation studies, similar results were found, but differences occurred due to the problematic assessment of consciousness. CONCLUSIONS: Sequential assessment of scores in intensive care could identify high risk patients, but with some degree of uncertainty. Therefore, the scores should only be used by those familiar with their limitations and risks.

APACHE↗
PubMed2003

Decision making under internal uncertainty: the case of multiple-choice tests with different scoring rules.

This paper assesses framing effects on decision making with internal uncertainty, i.e., partial knowledge, by focusing on examinees' behavior in multiple-choice (MC) tests with different scoring rules. In two experiments participants answered a general-knowledge MC test that consisted of 34 solvable and 6 unsolvable items. Experiment 1 studied two scoring rules involving Positive (only gains) and Negative (only losses) scores. Although answering all items was the dominating strategy for both rules, the results revealed a greater tendency to answer under the Negative scoring rule. These results are in line with the predictions derived from Prospect Theory (PT) [Econometrica 47 (1979) 263]. The second experiment studied two scoring rules, which allowed respondents to exhibit partial knowledge. Under the Inclusion-scoring rule the respondents mark all answers that could be correct, and under the Exclusion-scoring rule they exclude all answers that might be incorrect. As predicted by PT, respondents took more risks under the Inclusion rule than under the Exclusion rule. The results illustrate that the basic process that underlies choice behavior under internal uncertainty and especially the effect of framing is similar to the process of choice under external uncertainty and can be described quite accurately by PT.

Choice Behavior↗
PubMed1998

Caring for terminally ill persons: comparative analysis of attitudes (thanatophobia) of practicing physicians, student nurses, and medical students.

To investigate why some caregivers desire to avoid patients with terminal illnesses, a thanatophobia scale assessing caregivers' uncomfortable feelings and sense of helplessness was developed and evaluated among practicing physicians and student nurses and medical students. As a group, student nurses scored lower on the thanatophobia scale than practicing physicians and medical students. Higher scores on intolerance to clinical uncertainty were associated with higher thanatophobia scores in all groups. Scores for depressed mood, decreased sensitivity, and Machiavellianism were statistically significant predictors in some groups. Higher thanatophobia scores also predicted lower scores for ratings of self-esteem in caring for elderly patients. Among senior medical students, those with lower thanatophobia scores tended to enter primary care residencies. Health professional educators may find this scale helpful both in pinpointing sources of caregivers' angst and useful in counseling students in management of terminally ill persons.

Adult↗
PubMed2005

How robust are hospital ranks based on composite performance measures?

BACKGROUND: Composite indices of healthcare performance are an aggregation of underlying individual performance measures. They are increasingly being used to rank healthcare organizations. Although composite indicators present the "big picture" in a way that is easy to interpret, misleading conclusions may be drawn if attention is not paid to key methodological issues in their construction. OBJECTIVES: We examine variability in performance measures in the context of the construction and use of composite measures. We illustrate how variability in the underlying data and the resulting composite may undermine the robustness of performance measures in health care. We also illustrate how variation in the methodological rules applied to aggregate the individual indicators can have an important impact on composite scores. METHODS: We use data for 117 English acute hospitals to illustrate the generic methodological issues. The variance in performance measures is partitioned into "controllable" and "uncontrollable" elements. We create a composite index from the underlying performance indicators and use Monte Carlo simulations to examine the robustness of the composite. RESULTS: Random variation beyond the control of organizations gives rise to considerable uncertainty in hospital scores. Composites are also sensitive to changes made to the weighting system and to the aggregation rules. Some hospitals can jump almost half of the league table as a result of subtle changes. CONCLUSIONS: Great care is warranted in interpreting the results of composite performance measures. Suggestions for their future development are made.

Benchmarking↗
PubMedDate not supplied

Uncertainty and psychologic stress after coronary angioplasty and coronary bypass surgery.

OBJECTIVE: To examine the trajectory of uncertainty and symptoms of psychologic stress during the first 3 months after coronary angioplasty and coronary bypass surgery and to study the impact of social support on uncertainty and psychologic stress in these patient populations. DESIGN: Descriptive, correlative. SETTING: Urban community, at-home interviews. PATIENTS: Male patients with angioplasty (n = 22) and bypass (n = 25) at 1 and 3 months after treatment. Age range was 39 to 75 years (mean 58 years). OUTCOME MEASURES: Mishel Uncertainty in Illness scores, General Health Questionnaire scores, and Perceived Social Support Scale scores. INTERVENTION: Patients underwent either percutaneous transluminal coronary angioplasty or coronary artery bypass grafting as treatment for coronary artery disease. RESULTS: Data were analyzed with repeated measures analysis of variance and Pearson correlation coefficients. Results showed that at both time periods angioplasty patients were more uncertain than bypass patients (p < 0.05), and that regardless of procedure, patients reported fewer symptoms of psychologic stress at 3 months than at 1 month (p < 0.01). Patients with high social support had less uncertainty and psychologic stress than patients with low support (p < 0.05). Analysis of the social support and treatment group interaction showed that angioplasty patients with low perceived social support had significantly more psychologic stress than angioplasty patients with high support (p < 0.01). Analysis of the correlations between uncertainty and psychologic stress in the angioplasty and bypass grafting procedure groups after control for social support revealed that social support was a significant mediator of the relationship between uncertainty and stress only among patients undergoing percutaneous transluminal coronary angioplasty. There was little evidence of a mediating role for social support in the coronary artery bypass grafting group. CONCLUSIONS: These results suggest that angioplasty patients may be in particular need of interventions aimed at reducing uncertainty, and that interventions that increase social support could be important in achieving this reduction.

Adult↗
PubMed1995

Subjective interpretation, laboratory error and the value of forensic DNA evidence: three case studies.

This article discusses two factors that may profoundly affect the value of DNA evidence for proving that two samples have a common source: uncertainty about the interpretation of test results and the possibility of laboratory error. Three case studies are presented to illustrate the importance of the analyst's subjective judgments in interpreting some RFLP-based forensic DNA tests. In each case, the likelihood ratio describing the value of DNA evidence is shown to be dramatically reduced by uncertainty about the scoring of bands and the possibility of laboratory error. The article concludes that statistical estimates of the frequency of matching genotypes can be a misleading index of the value of DNA evidence, and that more adequate indices are needed. It also argues that forensic laboratories should comply with the National Research Council's recommendation that forensic test results be scored in a blind or objective manner.

DNA↗
PubMed2006

Fourier transform infrared (FT-IR) spectroscopy in bacteriology: towards a reference method for bacteria discrimination.

Rapid and reliable discrimination among clinically relevant pathogenic organisms is a crucial task in microbiology. Microorganism resistance to antimicrobial agents increases prevalence of infections. The possibility of Fourier transform infrared (FT-IR) spectroscopy to assess the overall molecular composition of microbial cells in a non-destructive manner is reflected in the specific spectral fingerprints highly typical for different microorganisms. With the objective of using FT-IR spectroscopy for discrimination between diverse microbial species and strains on a routine basis, a wide range of chemometrics techniques need to be applied. Still a major issue in using FT-IR for successful bacteria characterization is the method for spectra pre-processing. We analyzed different spectra pre-processing methods and their impact on the reduction of spectral variability and on the increase of robustness of chemometrics models. Different types of the Enterococcus faecium bacterial strain were classified according to chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis (PFGE). Samples were collected from human patients. Collected FT-IR spectra were used to verify if the same classification was obtained. In order to further optimize bacteria classification we investigated whether a selected combination of the most discriminative spectral regions could improve results. Two different variable selection methods (genetic algorithms (GAs) and bootstrapping) were investigated and their relative merit for bacteria classification is reported by comparing with results obtained using the entire spectra. Discriminant partial least-squares (Di-PLS) models based on corrected spectra showed improved predictive ability up to 40% when compared to equivalent models using the entire spectral range. The uncertainty in estimating scores was reduced by about 50% when compared to models with all wavelengths. Spectral ranges with relevant chemical information for Enterococcus faecium bacteria discrimination were outlined.

Bacterial Typing Techniques↗