Phytoplankton Producer Species and Transformation of Released Compounds over Time Define Bacterial Communities following Phytoplankton Dissolved Organic Matter Pulses.

Phytoplankton-bacterium interactions are mediated, in part, by phytoplankton-released dissolved organic matter (DOMp). Two factors that shape the bacterial community accompanying phytoplankton are (i) the phytoplankton producer species, defining the initial composition of released DOMp, and (ii) the DOMp transformation over time. We added phytoplankton DOMp from the diatom Skeletonema marinoi and the cyanobacterium Prochlorococcus marinus MIT9312 to natural bacterial communities from the eastern Mediterranean and determined the bacterial responses over a time course of 72 h in terms of cell numbers, bacterial production, alkaline phosphatase activity, and changes in active bacterial community composition based on rRNA amplicon sequencing. Both DOMp types were demonstrated to serve the bacterial community as carbon and, potentially, phosphorus sources. Bacterial communities in diatom-derived DOM treatments maintained higher Shannon diversities throughout the experiment and yielded higher bacterial production and lower alkaline phosphatase activity compared to cyanobacterium-derived DOM after 24 h of incubation (but not after 48 and 72 h), indicating greater bacterial usability of diatom-derived DOM. Bacterial communities significantly differed between DOMp types as well as between different incubation times, pointing to a certain bacterial specificity for the DOMp producer as well as a successive utilization of phytoplankton DOM by different bacterial taxa over time. The highest differences in bacterial community composition with DOMp types occurred shortly after DOMp additions, suggesting a high specificity toward highly bioavailable DOMp compounds. We conclude that phytoplankton-associated bacterial communities are strongly shaped by the phytoplankton producer as well as the transformation of its released DOMp over time. IMPORTANCE Phytoplankton-bacterium interactions influence biogeochemical cycles of global importance. Phytoplankton photosynthetically fix carbon dioxide and subsequently release the synthesized compounds as dissolved organic matter (DOMp), which becomes processed and recycled by heterotrophic bacteria. Yet the importance of phytoplankton producers in combination with the time-dependent transformation of DOMp compounds on the accompanying bacterial community has not been explored in detail. The diatom Skeletonema marinoi and the cyanobacterium Prochlorococcus marinus MIT9312 belong to globally important phytoplankton genera, and our study revealed that DOMp of both species was selectively incorporated by the bacterial community. The producer species had the highest impact shortly after DOMp appropriation, and its effect diminished over time. Our results improve the understanding of the dynamics of organic matter produced by phytoplankton in the oceans as it is utilized and modified by cooccurring bacteria.

Phytoplankton exudates provide full nutrition to a subset of accompanying heterotrophic bacteria via carbon, nitrogen and phosphorus allocation.

Marine bacteria rely on phytoplankton exudates as carbon sources (DOCp). Yet, it is unclear to what extent phytoplankton exudates also provide nutrients such as phytoplankton-derived N and P (DONp, DOPp). We address these questions by mesocosm exudate addition experiments with spent media from the ubiquitous pico-cyanobacterium Prochlorococcus to bacterial communities in contrasting ecosystems in the Eastern Mediterranean - a coastal and an open-ocean, oligotrophic station with and without on-top additions of inorganic nutrients. Inorganic nutrient addition did not lower the incorporation of exudate DONp, nor did it reduce alkaline phosphatase activity, suggesting that bacterial communities are able to exclusively cover their nitrogen and phosphorus demands with organic forms provided by phytoplankton exudates. Approximately half of the cells in each ecosystem took up detectable amounts of Prochlorococcus-derived C and N, yet based on 16S rRNA sequencing different bacterial genera were responsible for the observed exudate utilization patterns. In the coastal community, several phylotypes of Aureimarina, Psychrosphaera and Glaciecola responded positively to the addition of phytoplankton exudates, whereas phylotypes of Pseudoalteromonas increased and dominated the open-ocean communities. Together, our results strongly indicate that phytoplankton exudates provide coastal and open-ocean bacterial communities with organic carbon, nitrogen and phosphorus, and that phytoplankton exudate serve a full-fledged meal for the accompanying bacterial community in the nutrient-poor eastern Mediterranean.

Validation of a photophobia symptom impact scale.

BACKGROUND: Routine assessment of photophobia in the clinical setting may underestimate the presence and severity of this condition. We aimed to develop and validate a questionnaire to improve evaluation of the impact of photophobia on activities of daily living, and to determine the relationship of this questionnaire to psychophysical assessment of light sensitivity thresholds. METHODS: We developed the 17-item Utah Photophobia Symptom Impact Scale (UPSIS-17) and compared its psychometric properties to the 8-item Korean Photophobia Questionnaire (KUMC-8). Ninety five subjects with or without light sensitivity completed both questionnaires; 72 also completed laboratory-based assessment of light sensitivity thresholds. We used Rasch analysis to evaluate instrument targeting, including internal consistency and reliability. Correlation analysis was used to assess the relationship between questionnaire scores and light sensitivity thresholds. RESULTS: We observed correlation between UPSIS-17 and KUMC-8, r = 0.72 (p < 0.0001). Higher UPSIS-17 scores correlated with light sensitivity thresholds, r = -0.42 (p < 0.0001), whereas KUMC-8 scores did not significantly correlate with light sensitivity thresholds, r = -0.21 (p = 0.072). UPSIS-17 showed better instrument targeting than KUMC-8 on Rasch analysis. Person-item maps allowed for identification of questions that could be removed without affecting questionnaire validity measures. CONCLUSION: This study resulted in a shortened, 12-item questionnaire. The UPSIS-12 retained significant correlation with both the KUMC-8 and light sensitivity thresholds, yielding a simpler tool for symptom assessment, while retaining validity. This expanded tool may be useful in clinical, as well as research settings, for collection of data about disability due to photophobia.

Minimal Clinically Important Difference After Carpal Tunnel Release Using the PROMIS Platform.

PURPOSE: In light of recently-proposed quality measures for carpal tunnel release (CTR), elucidating the minimal clinically important difference (MCID) for selected outcome measures will be important when interpreting treatment responses. Our purpose was to estimate the MCID of the Patient-Reported Outcomes Measurement Information System (PROMIS) instruments and the short Disabilities of the Arm, Shoulder, and Hand (QuickDASH) following CTR. METHODS: Adult patients undergoing isolated unilateral CTR between July 2014 and October 2016 were identified. Outcomes included the PROMIS Upper Extremity (UE) Computer Adaptive Test (CAT), Physical Function (PF) CAT, QuickDASH, and Pain Interference (PI) CAT. For inclusion, pretreatment baseline (within 60 days of surgery) and postoperative (6-90 days) UE or PF CAT scores were required, as well as a response on a 5-point Likert scale to the question "How much relief and/or improvement do you feel you have experienced as a result of your treatment?" The MCID was calculated using SD and minimum detectable change (MDC) distribution methods. RESULTS: In response to the Likert scale question, 88.6% of patients reported improvement at a mean of 14.8 days after surgery. The infrequency of patients reporting no change (5 of 44; 11.4%) precluded calculation of a statistically sound anchor-based MCID value. The MCID values, as calculated using the one-half SD method, were 3.6, 4.6, 10.4, and 3.4 for the UE CAT, PF CAT, QuickDASH, and PI CAT, respectively. CONCLUSIONS: We have calculated MCID values for the UE CAT, PF CAT, QuickDASH, and PI CAT for patients undergoing CTR. Although the small number of patients reporting no change and minimal change after surgery precluded an anchor-based MCID calculation, we report estimates using the one-half SD method for the MCID following CTR. CLINICAL RELEVANCE: These MCID estimates will be helpful when interpreting CTR clinical outcomes and for powering prospective trials.

Evaluation of Version 2.0 of the PROMIS Upper Extremity Computer Adaptive Test in Nonshoulder Upper Extremity Patients.

PURPOSE: The Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity Computer Adaptive Test (UE CAT) was recently updated to version 2.0 (v2.0). We hypothesized that the PROMIS UE CAT v2.0 would exhibit improved performance characteristics compared with the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) when administered to a nonshoulder upper extremity patient population. METHODS: The UE CAT v2.0, Physical Function (PF) CAT v2.0, and the QuickDASH were each prospectively administered via tablet computer to all patients presenting to a tertiary hand and upper extremity clinic between April 2017 and October 2017. Patient responses were analyzed, and the mean, range, floor and ceiling effect, and correlations between instruments were calculated. RESULTS: Among 825 patients, the mean UE CAT v2.0 score was 38.3 (SD 10.7) with a range of 15 to 61 and interquartile range of 15.4. The UE CAT v2.0 had a strong correlation with the QuickDASH (r = -0.749) and the PF CAT v2.0 (r = 0.719). No patient scored between 56 and 60, indicating a gap in scoring in that range. The UE CAT v2.0 demonstrated a floor effect of 1%, a ceiling effect of 6.9%, and a high internal consistency with a Cronbach alpha of 0.99. CONCLUSIONS: The PROMIS UE CAT v2.0 demonstrated improved ceiling effects, range, and a decreased gap in scoring compared with prior versions. Limitations of the PROMIS UE CAT v2.0 are still present, but updates have led to an incremental improvement over prior versions, demonstrating the ability to influence PROMIS instrument performance through upgrades. CLINICAL RELEVANCE: The updated PROMIS UE CAT v2.0 still demonstrates a ceiling effect and gap in scores at the upper end of the instrument, both of which may limit discrimination between different levels of upper extremity function for high-functioning patients.

Psychometric evaluation of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function and Pain Interference Computer Adaptive Test for subacromial impingement syndrome.

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Computer Adaptive Test (CAT) was previously validated for rotator cuff disease and shoulder instability. This study evaluated the psychometric properties of the PROMIS Physical Function (PF) CAT, PROMIS Pain Interference (PI) CAT, and the American Shoulder and Elbow Surgeons (ASES) Shoulder Function Score for subacromial impingement syndrome. METHODS: PROMIS PF CAT, PI CAT, and ASES (Pain, Function, Total) were collected on all visits for 2 surgeons between January 2016 and August 2016. New patients, aged 18 years and older, were selected by International Classification of Diseases code for impingement syndrome of the shoulder. The mean number of questions answered determined efficiency. Person-item maps were created to determine ceiling and floor effects as well as person reliability. Convergent validity was determined by comparison of PROMIS domains to ASES scores with Pearson correlations. RESULTS: For PROMIS PF CAT, the mean number of items answered was 4.54 (range 4-12). The ceiling effect was 1.56%, and the floor effect was 3.13%. The person reliability was 0.94. Pearson correlation coefficients between the PF CAT and ASES were 0.664 (ASES Function), 0.426 (ASES Pain), and 0.649 (ASES Total). For PROMIS PI CAT, the mean number of items answered was 4.27 (range 3-11). The ceiling effect was 4.69%, and the floor effect was 8.33%. The person reliability was 0.92. Pearson correlation coefficients between the PI CAT and ASES were: 0.667 (ASES Function), 0.594 (ASES Pain), and 0.729 (ASES Total). CONCLUSIONS: The psychometric properties of PROMIS PF and PI CATs were favorable for subacromial impingement syndrome.

Application of machine learning for diagnostic prediction of root caries.

OBJECTIVE: This study sought to utilise machine learning methods in artificial intelligence to select the most relevant variables in classifying the presence and absence of root caries and to evaluate the model performance. BACKGROUND: Dental caries is one of the most prevalent oral health problems. Artificial intelligence can be used to develop models for identification of root caries risk and to gain valuable insights, but it has not been applied in dentistry. Accurately identifying root caries may guide treatment decisions, leading to better oral health outcomes. METHODS: Data were obtained from the 2015-2016 National Health and Nutrition Examination Survey and were randomly divided into training and test sets. Several supervised machine learning methods were applied to construct a tool that was capable of classifying variables into the presence and absence of root caries. Accuracy, sensitivity, specificity and area under the receiver operating curve were computed. RESULTS: Of the machine learning algorithms developed, support vector machine demonstrated the best performance with an accuracy of 97.1%, precision of 95.1%, sensitivity of 99.6% and specificity of 94.3% for identifying root caries. The area under the curve was 0.997. Age was the feature most strongly associated with root caries. CONCLUSION: The machine learning algorithms developed in this study perform well and allow for clinical implementation and utilisation by dental and nondental professionals. Clinicians are encouraged to adopt the algorithms from this study for early intervention and treatment of root caries for the ageing population of the United States, and for attaining precision dental medicine.

Assessing spousal support and health in an aging population: support and strain amidst changing social dynamics.

This study examined the role of relationship quality on physical and psychological health among older adults. It included 2,298 adults aged 50 and older who participated in the Midlife in the US national longitudinal study of health and well-being. We assessed the effect of spousal support and strain on psychological and physical health, controlling for age, education, income, depression levels and prior health. Results indicated that spousal support and strain affected psychological health but not physical health. Despite prior research showing an association between marital quality and physical health, this study did not support the conceptualization that relationship quality measured by spousal support or strain has a direct effect on long-term health in this sample of older adults. This study does not preclude the presence of a mediated or moderated association between relationship quality and physical health. Higher levels of spousal support are associated with positive psychological health among adults over age 50 while spousal strain is associated with negative psychological health. This study supports the premise that relationship quality has an ongoing impact on the psychological health of mature adults, bolstering arguments to include psychological health screening and couples relationship education among health services provided to older adults.

Mini-review: Phytoplankton-derived polysaccharides in the marine environment and their interactions with heterotrophic bacteria.

Within the wealth of molecules constituting marine dissolved organic matter, carbohydrates make up the largest coherent and quantifiable fraction. Their main sources are from primary producers, which release large amounts of photosynthetic products - mainly polysaccharides - directly into the surrounding water via passive and active exudation. The organic carbon and other nutrients derived from these photosynthates enrich the 'phycosphere' and attract heterotrophic bacteria. The rapid uptake and remineralization of dissolved free monosaccharides by heterotrophic bacteria account for the barely detectable levels of these compounds. By contrast, dissolved combined polysaccharides can reach high concentrations, especially during phytoplankton blooms. Polysaccharides are too large to be taken up directly by heterotrophic bacteria, instead requiring hydrolytic cleavage to smaller oligo- or monomers by bacteria with a suitable set of exoenzymes. The release of diverse polysaccharides by various phytoplankton taxa is generally interpreted as the deposition of excess organic material. However, these molecules likely also fulfil distinct, yet not fully understood functions, as inferred from their active modulation in terms of quality and quantity when phytoplankton becomes nutrient limited or is exposed to heterotrophic bacteria. This minireview summarizes current knowledge regarding the exudation and composition of phytoplankton-derived exopolysaccharides and acquisition of these compounds by heterotrophic bacteria.

Extensive nitrification and active ammonia oxidizers in two contrasting coastal systems of the Baltic Sea.

Nitrification is important in nitrogen (N) cycling of aquatic environments, but knowledge about its regulation and importance is sparse. Here we examined nitrification and ammonia oxidizers in the Baltic Sea. We investigated two sites with different catchment characteristics (agricultural and forest), the Bay of Gdánsk (south) and the Öre Estuary (north), and measured pelagic nitrification rates and abundance, composition and expression of ammonia monooxygenase (amoA) genes. Highest nitrification rates were found in the nutrient rich Bay of Gdansk. Interestingly, abundances of ammonia-oxidizing archaea (AOA) and bacteria (AOB) were orders of magnitude lower than reported from other sites. Although AOA were most abundant at both sites, the highest expression levels were from AOB. Interestingly, few AOA and AOB taxa dominated amoA gene expression, with a Nitrosomarinus related phylotype showing widespread expression. AOA and AOB communities differed between sites and depths, respectively, with the composition in rivers being distinct. A storm event, causing an even depth distribution of nitrification and particles in the Bay of Gdansk, indicated that the presence of particles stimulate nitrification. The study highlights coastal regions as dynamic sites of extensive pelagic nitrification, which may affect local food web dynamics and loss of N mediated by denitrification.

The response of the marine nitrogen cycle to ocean acidification.

Ocean acidification (OA), arising from the influx of anthropogenically generated carbon, poses a massive threat to the ocean ecosystems. Our knowledge of the effects of elevated anthropogenic CO2 in marine waters and its effect on the performance of single species, trophic interactions, and ecosystems is increasing rapidly. However, our understanding of the biogeochemical cycling of nutrients such as nitrogen is less advanced and lacks a comprehensive overview of how these processes may change under OA. We conducted a systematic review and meta-analysis of eight major nitrogen transformation processes incorporating 49 publications to synthesize current scientific understanding of the effect of OA on nitrogen cycling in the future ocean by 2100. The following points were identified by our meta-analysis: (a) Diazotrophic nitrogen fixation is likely enhanced by 29% ± 4% under OA; (b) species- and strain-specific responses of nitrogen fixers to OA were detectable, which may result in alterations in microbial community composition in the future ocean; (c) nitrification processes were reduced by a factor of 29% ± 10%; (d) declines in nitrification rates were not reflected by nitrifier abundance; and (e) contrasting results in unispecific culture experiments versus natural communities were apparent for nitrogen fixation and denitrification. The net effect of the nitrogen cycle process responses also suggests there may be a shift in the relative nitrogen pools, with excess ammonium originating from CO2 -fertilized diazotrophs. This regenerated inorganic nitrogen may recycle in the upper water column increasing the relative importance of the ammonium-fueled regenerated production. However, several feedback mechanisms with other chemical cycles, such as oxygen, and interaction with other climate change stressors may counteract these findings. Finally, our review highlights the shortcomings and gaps in current understanding of the potential changes in nitrogen cycling under future climate and emphasizes the need for further ecosystem studies.

Modified dynamic gait index and limits of stability in myotonic dystrophy type 1.

INTRODUCTION: The purpose of this study was to describe and compare the performance of balance and walking tests in relation to self-reported fall history in adults with myotonic dystrophy type 1 (DM1). METHODS: Twenty-two (13 male) participants with DM1 completed, a 6-month fall history questionnaire, the modified Dynamic Gait Index (mDGI), limits of stability (LoS) testing, and 10-m walking tests. RESULTS: Mean (SD) falls in 6 months was 3.7 (3.1), and 19 (86%) participants reported at least 1 fall. Significant differences in mDGI scores (P = 0.006) and 10-m fast walking gait velocity (P = 0.02) were found between those who had been classified as "fallers" and those who had been classified as "nonfallers." Significant correlations were found between mDGI scores and 10-m walking time. DISCUSSION: Falls are common in DM1, and the mDGI may have potential to distinguish fallers from nonfallers, whereas the LoS failed to detect such impairment. Future studies should further explore use of the mDGI in DM1. Muscle Nerve 58: 694-699, 2018.

The Relationship of PROMIS Pain Interference and Physical Function Scales.

Objectives: To examine the relationship between the Patient Reported Outcome Measurement Information System (PROMIS) Pain Interference (PI) and PROMIS Physical Function (PF) scales in patients with spinal pain at a university spine center. Design: Retrospective analysis of prospectively collected patient-reported outcome data at a university spine clinic. Pearson correlation was done to examine the relationship of the PROMIS PF and PROMIS PI scores. Age, gender, and race were analyzed by subgroups on the PROMIS Physical Function and Pain Interference score. Linear regression analyzed predictive relationships. Statistical significance was set at P < 0.05. Results: A total of 1,992 participants completed an assessment, with 1,923 completing the PF CAT and 1,927 the PI CAT. Participants' mean age was 52.8 years (range = 18-94 years, SD = 6.5 years). Correlation analysis of the PROMIS PF with the PROMIS PI showed a Pearson correlation value of -0.717 (P < 0.05). There was a strong linear relationship with a high negative correlation between PF CAT and PI CAT. The PI CAT predicted PF CAT scores (ß = -0.707, P < 0.001). Conclusions: For patients with pain from spinal origin, there is a strong negative correlation between self-reported physical function and pain interference related to physical, social, and mental health. The predictive relationship of function from pain scores supports the PROMIS PI being used as an important adjunct measure of physical function in patients with spinal pain.

What Are the MCIDs for PROMIS, NDI, and ODI Instruments Among Patients With Spinal Conditions?

BACKGROUND: As new Patient-Reported Outcomes Measurement Information System (PROMIS) instruments are incorporated into clinical practice, determining how large a change on these instruments represents a clinically relevant difference is important; the metric that describes this is the minimum clinically important difference (MCID). Prior research on MCIDs of the Neck Disability Index (NDI) and Oswestry Disability Index (ODI) has produced values ranging from 5 to 10 points, but these measures have not been presented in relation to MCID values of PROMIS instruments. QUESTIONS/PURPOSES: To establish a comprehensive repository of MCID values calculated both with distribution-based and anchor-based methods for four outcomes instruments in spine care, we asked: (1) What are the MCIDs of the PROMIS Physical Function (PF); (2) the PROMIS Pain Interference (PI); (3) the NDI; and (4) the ODI among spine patients? METHODS: We conducted a prospective study of previously tested diagnostic measures on 1945 consecutive patients with a reference standard applied. All patients aged 18 years and older visiting an orthopaedic spine clinic between October 2013 and January 2017 completed the PROMIS PF and PI, NDI, and ODI on tablet computers before their clinic visits. Patients were grouped by change level (self-report of meaningful change versus slight or no change) using an anchor question in comparison to baseline. Descriptive statistics, two anchor-based MCID values (mean change and receiver operating characteristic curve), and five distribution-based values (SD at 1/2 and 1/3 values and minimum detectable change [MDC] at 90%, 95%, and 99%) were analyzed four different times between 3 months and > 6 months of followup. A total of 1945 included patients with a wide range of spine conditions and varying treatments had a mean age of 58 years (SD = 15.5), were 51% (988 of 1945) male, 90% (1754 of 1945) self-identified as white, and 5% (94 of 1945) as Hispanic with 1% to 2% of patients refusing participation. RESULTS: The PROMIS PF mean change scores in the changed group (much worse, worse, improved, or much improved) ranged between 7 and 8 points. MCID values ranged from 3 to 23 points depending on the method of calculation with a median of 8. For the PROMIS PI, mean change scores ranged from 8 to 9 points and MCID values from 1 to 24 points with a median of 8. For the NDI, mean change scores ranged from 13 to 18 points and MCID values ranged from 6 to 43 points with a median of 18. For the ODI, mean change ranged from 17 to 19 points and MCID values ranged from 7 to 51 points with a median of 24. For each instrument, distribution-based SD yielded the smallest values, followed by anchor-based methods, with MDC yielding the largest MCID values. CONCLUSIONS: This study uses a range of methods for determining MCIDs of the PROMIS PF and PI, NDI, and ODI from anchor-based to distribution-based methods. MCIDs do not have a static value for a given outcome measure, but have a range of values and are dependent on the method calculated. The lowest MCIDs identified for the NDI and ODI are consistent with prior studies, but those at the upper range are much higher. Anchor-based methods are thought to be most relevant in the clinical setting and are more easily understood by clinicians, whereas the distribution-based MCIDs are useful in understanding population breadth. Lower MCID values may be most appropriate for screening purposes or low-risk effects, and the median or higher MCID values should be used for high-risk effects or outcomes. LEVEL OF EVIDENCE: Level I, diagnostic study.

Psychometrics of the Patient-Reported Outcomes Measurement Information System Physical Function instrument administered by computerized adaptive testing and the Disabilities of Arm, Shoulder and Hand in the orthopedic elbow patient population.

BACKGROUND: This study evaluated the psychometric properties of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) instrument administered through computerized adaptive testing (CAT) compared with the traditional full-length Disabilities of the Arm, Shoulder and Hand (DASH). METHODS: The PROMIS PF CAT and the DASH were administered to 1759 patients seeking care for elbow conditions. This study used Rasch partial credit modeling to analyze the instruments with item fit, internal reliability, response category thresholds, dimensionality, local independence, gender differential item functioning, and floor and ceiling effects. RESULTS: The PROMIS PF CAT and DASH had satisfactory item fit for all but 1 item on both measures. Internal reliabilities were high for both measures. Two items on the DASH and 4 items on the PF CAT showed nonordered category thresholds. Unidimensionality was adequate, and local independence was supported for both instruments. Gender bias was found for 4 items on the PF CAT and 12 items on the DASH. Both measures had adequate instrument targeting and satisfactory floor and ceiling effects. CONCLUSION: The PROMIS PF CAT and the DASH both showed sufficient unidimensionality, good item fit, and good local independence with the exception of high levels of gender item bias, particularly for the DASH. Further scale evaluation should address item bias and item response categories for these instruments. Overall, the PROMIS PF CAT is an effective outcome instrument to measure function in patients with elbow disorders that requires significantly fewer questions than the DASH.

Profiling Arthritis Pain with a Decision Tree.

BACKGROUND: Arthritis is the leading cause of work disability and contributes to lost productivity. Previous studies showed that various factors predict pain, but they were limited in sample size and scope from a data analytics perspective. OBJECTIVES: The current study applied machine learning algorithms to identify predictors of pain associated with arthritis in a large national sample. METHODS: Using data from the 2011 to 2012 Medical Expenditure Panel Survey, data mining was performed to develop algorithms to identify factors and patterns that contribute to risk of pain. The model incorporated over 200 variables within the algorithm development, including demographic data, medical claims, laboratory tests, patient-reported outcomes, and sociobehavioral characteristics. RESULTS: The developed algorithms to predict pain utilize variables readily available in patient medical records. Using the machine learning classification algorithm J48 with 50-fold cross-validations, we found that the model can significantly distinguish those with and without pain (c-statistics = 0.9108). The F measure was 0.856, accuracy rate was 85.68%, sensitivity was 0.862, specificity was 0.852, and precision was 0.849. CONCLUSION: Physical and mental function scores, the ability to climb stairs, and overall assessment of feeling were the most discriminative predictors from the 12 identified variables, predicting pain with 86% accuracy for individuals with arthritis. In this era of rapid expansion of big data application, the nature of healthcare research is moving from hypothesis-driven to data-driven solutions. The algorithms generated in this study offer new insights on individualized pain prediction, allowing the development of cost-effective care management programs for those experiencing arthritis pain.

Success of chemolithoautotrophic SUP05 and Sulfurimonas GD17 cells in pelagic Baltic Sea redox zones is facilitated by their lifestyles as K- and r-strategists.

Chemolithoautotrophic sulfur-oxidizing and denitrifying Gamma- (particularly the SUP05 cluster) and Epsilonproteobacteria (predominantly Sulfurimonas subgroup GD17) are assumed to compete for substrates (electron donors and acceptors) in marine pelagic redox gradients. To elucidate their ecological niche separation we performed 34 S0 , 15 NO3- and H13 CO3- stable-isotope incubations with water samples from Baltic Sea suboxic, chemocline and sulfidic zones followed by combined phylogenetic staining and high-resolution secondary ion mass spectrometry of single cells. SUP05 cells were small-sized (0.06-0.09 µm3 ) and most abundant in low-sulfidic to suboxic zones, whereas Sulfurimonas GD17 cells were significantly larger (0.26-0.61 µm3 ) and most abundant at the chemocline and below. Together, SUP05 and GD17 cells accumulated up to 48% of the labelled substrates but calculation of cell volume-specific rates revealed that GD17 cells incorporated labelled substrates significantly faster throughout the redox zone, thereby potentially outcompeting SUP05 especially at high substrate concentrations. Thus, in synopsis with earlier described features of SUP05/GD17 we conclude that their spatially overlapping association in stratified sulfidic zones is facilitated by their different lifestyles: whereas SUP05 cells are streamlined, non-motile K-strategists adapted to low substrate concentrations, GD17 cells are motile r-strategists well adapted to fluctuating substrate and redox conditions.

The relationship between family support; pain and depression in elderly with arthritis.

The prevalence and chronic nature of arthritis make it the most common cause of disability among U.S.A adults. Family support reduces the negative impact of chronic conditions generally but its role in pain and depression for arthritic conditions is not well understood. A total of 844 males (35.0%) and 1567 females (65.0%) with arthritic conditions (n = 2411) were drawn from the 2012 Health and Retirement Study to examine the effect of family support on pain and depressive symptoms. Using regression analysis and controlling for age, ethnicity, gender, marital/educational status and employment/income, physical function/disability status, pain and antidepressant medications, and other clinical indicators of chronic health conditions, we examined the effects of family support (spouse, children, other) on pain and depression levels. Results indicated that depressive symptoms decreased significantly with strong family and spousal support (p < .05). Pain decreased as support levels increased, but was non-statistically significant. This study provides new insights into the relationship between family support, pain, and depression for individuals with arthritis. Future longitudinal studies are needed to evaluate family support and relationships over a wider spectrum of demographics.

Examination of the PROMIS upper extremity item bank.

STUDY DESIGN: Clinical measurement. INTRODUCTION: The psychometric properties of the PROMIS v1.2 UE item bank were tested on various samples prior to its release, but have not been fully evaluated among the orthopaedic population. PURPOSE OF THE STUDY: This study assesses the performance of the UE item bank within the UE orthopaedic patient population. METHODS: The UE item bank was administered to 1197 adult patients presenting to a tertiary orthopaedic clinic specializing in hand and UE conditions and was examined using traditional statistics and Rasch analysis. RESULTS: The UE item bank fits a unidimensional model (outfit MNSQ range from 0.64 to 1.70) and has adequate reliabilities (person = 0.84; item = 0.82) and local independence (item residual correlations range from -0.37 to 0.34). Only one item exhibits gender differential item functioning. Most items target low levels of function. DISCUSSION: The UE item bank is a useful clinical assessment tool. Additional items covering higher functions are needed to enhance validity. CONCLUSIONS: Supplemental testing is recommended for patients at higher levels of function until more high function UE items are developed. LEVEL OF EVIDENCE: 2c.

The Association Between Perceived Health Status and Health Information Communication Channels.

Varying types of health information sources may influence health outcomes, but not much is known about their impact. The purpose of our study was to explore the association between health information sources and individuals' health status. A total of 14,966 participants who responded to the Annenberg National Health Communication Survey between 2005 and 2012 were included. Controlling for demographics, comorbidities, communication patterns, and socioeconomic status, we utilized regression analysis to examine the relationship between sources of health information and perceived health status. Included in the study were a total of 8,103 females and 6,863 males between 18 and 101 years old (M = 49.14, SD = 16.13). Health information from the Internet and pharmaceutical companies was significantly associated with better health status (p < .05), whereas information from social media, health care apps, news outlets, and health care companies was not. Information from the Internet was significantly associated with better health status, suggesting that health information from the Internet may have benefits. However, use of social media and health care apps did not relate to better health status, which may indicate that these sources are not as useful to consumers or that these sources have not yet saturated the health information marketplace.