Sambandsanalys av surveydata kompliceras av förekomsten av slumpfel och metodeffekter i de avgivna svaren. Dessa felkällor kan leda till betydande över- eller underskattning av sambanden mellan undersökta variabler, och riskerar att leda till felaktiga slutsatser. En sedan länge känd metod för att estimera och kontrollera för slumpfel och metodeffekter i enkätdata är den så kallade Multitrait Multimethod-metoden (MTMM). Nackdelen med MTMM-metoden är att den kräver att varje fråga som ska analyseras ställs minst tre gånger i samma enkät, vilket gör att ansatsen i praktiken oftast inte är möjlig att tillämpa. Sedan 2012 finns dock ett verktyg, SQP 2.0, som gör det möjligt att skatta slumpfel och metodeffekter i enkätdata utan att genomföra MTMM-experiment. Den här uppsatsen utvärderar prediktionerna från SQP 2.0 på en enkät om arbetslivsrelaterade frågor besvarad av svenska och brittiska respondenter. Programvarans prediktioner jämförs med resultat från MTMM-experiment, och effekten på sambandsanalysen av att tillämpa SQP-programvarans prediktioner av slumpfel och metodeffekter studeras. Slutsatserna från studien är att SQP 2.0 ger predicerade värden för slumpfel och metod-effekter som ligger nära de MTMM-estimerade i de flesta fall, men att betydande avvikelser också förekommer. Vidare konstateras att korrigering för slumpfel och metodeffekter har en betydande effekt på absolutvärdet av korrelationerna mellan variabler under de studerande förhållandena: korrelationerna i det studerade fallet ökar kraftigt efter justering. Korrelationernas relativa storlek förändras i mindre utsträckning, men för en enkät med mer varierade frågetyper kan också dessa påverkas kraftigt. / Correlation analysis of survey data is complicated by the presence of random errors and method effects in the answers given. These factors can lead to significant over- or underestimation of the correlations between variables. A well-established method for estimating and controlling for random error and method effects in survey data is the Multitrait-Multimethod (MTMM) approach. The disadvantage of this method is that it requires that each survey item to be analysed is asked multiple times in the same survey, making the approach hard to use in many practical situations. Since 2012 there is a tool available, SQP 2.0, to predict random errors and method effects in survey data without performing MTMM experiments. This paper evaluates the use of predictions from the SQP 2.0 software on the correlation analysis of a survey of work related matters answered by Swedish and British respondents. The software's predictions are compared with results from MTMM experiments, and the effect on the correlations of applying the SQP software's predictions of random errors and method effects are studied. The conclusion of the study is that SQP 2.0 gives predicted values for random error and method effects that are close to the MTMM-estimates in most cases, but that considerable deviations also occur. It is further concluded that controlling for random error and method effects has a significant effect on the absolute values of the correlations between variables in the studied cases: the correlations in the study increase substantially after adjustment. The relative sizes of the correlations between variables change to a lesser extent, but a questionnaire with more varied question types may have lead to different results in this respect.

Sammanfattning Titel: Imorgon blir det börsfall! En studie om hur olika börser påverkar varandra i fördröjning. Seminariedatum: 28 maj, 2012 Ämne/kurs: FEK 61-90 Kandidatuppsats i Corporate Finance, 15 poäng  Författare: Stefan Koch, Malin Molin Handledare: Hans Mörner Examinator: Kent Sahlgren Nyckelord: Anomali, anomalier, veckodagseffekt, måndagseffekt, index, korrelation, S&P 500, OMXS 30, effektiva marknadshypotesen Syfte: Att undersöka ifall en eventuell anomali på det svenska OMXS 30 indexet eller det amerikanska S&P 500 ger en effekt på nästföljande dag på det motsatta indexet. Om en veckodagseffekt kan påvisas och den fördröjda korrelationen mellan indexen är tillräckligt stark kan metoden användas för att generera överavkastning.   Metod: Vi använder oss av en kvantitativ ansats för att med hjälp av statistiska metoder svara på vår problemformulering. De metoder vi har använt är hypotestestning av medelvärden med ett z test, beräknat korrelationskoefficienten mellan de två indexen och utfört en multipel regressionsanalys med dummyvariabler. Slutsats: Genom vår analys kom vi fram till att en veckodagseffekt inte kan påvisas på någon av de två undersökta indexen. En korrelation kunde finnas mellan de två indexen, däremot går det att ifrågasätta om korrelationens styrka är tillräckligt stark att handla utifrån. För att generera överavkastning krävs dessutom att den extra avkastning som genereras med hjälp utav vår metod med korta aktieaffärer överstiger den eventuella transaktionskostnaden som uppstår vid aktiehandel, något vi starkt betvivlar att den gör. / Abstract Title: Tomorrow the market falls! A study about how different stock markets affect each other in delay. Date of seminar: May, 28th, 2012 Course: FEK 61-90 Bachelor Thesis in Corporate Finance, 15 credits Authors: Stefan Koch, Malin Molin Advisor: Hans Mörner Examiner: Kent Sahlgren Key words: Anomaly, anomalies, day-of-the-week effect, weekend effect, index, correlation, S&P 500, OMXS 30, effective market hypothesis Objective: To examine whether a potential anomaly on the Swedish OMXS 30 index or the American S&P 500 has an effect on the next day on the opposite index. If a day-of-the-week effect can be proved and the delayed correlation between the indices is strong enough, our method could be used to generate excess returns. Methodology: We use a quantitative approach and statistic methods to answer our problem formulation. The methods we have been using are hypothesis testing of mean values with a z-test, calculations of correlation coefficients between the indices, and a multiple regression analysis with dummy variables. Conclusions: Through our analysis we found out that there was no day-of-the-week effect on any of the two examined indices. We could find a correlation between the two indices; however, we question whether the correlation is strong enough to trade on. To get excess returns it is required that the extra return that would be generated through our method with short trades exceed eventual transaction costs that occur through stock trading, something we strongly doubt that it would.

Syfte och frågeställningar Syftet med studien var att undersöka för elitorienterare resultaten vid och korrelationen mellan ett så kallat 5 minuters pyramidtest (5MPT) och ett maximalt test för bestämning av maximalt syreupptag (VO2max) på rullband. Frågorna vi ställde oss var: Vilken korrelation föreligger mellan 5MPT och ett bestämt VO2max på rullband hos elitorienterare? Hur ser en jämförelse ut mellan uppmätt samt beräknat VO2max? Vilken är reliabiliteten för 5MPT? Hur ser ekvationen ut för att beskriva sambandet mellan dessa två olika maxtester? Metod I valideringsstudien deltog 16 elitorienterare (6 kvinnor och 10 män) i åldrarna 17 till 37 år. De två testerna som genomfördes var 5MPT och bestämning av VO2max på rullband. 5MPT är ett skytteltest som är fem minuter långt, där testpersonen (tp) tar sig fram och tillbaka mellan två stolpar (sträcka 5.5 m) där en vertikal trappa (formad likt en pyramid) passeras under varje vända. Antalet vändor, skattad ansträngning samt hjärtfrekvens (HF) registrerades. Utvecklad power (effekt) erhölls genom produkten av vikt, gravitation, antal vändor, höjd på högsta plinten (0,62 m) dividerat med total duration i 5MPT. Testet för att bestämma VO2max utfördes med löpning på ett motordrivet rullband. Under den första minuten av testet sprang tp på en hastighet av 8km/h (kvinnor) respektive10km/h (män) utan lutning. För varje minut ökades hastigheten med 1km/h. Lutningen höjdes med en grad efter minut ett och därefter med 0,5 grader/minut. Testet pågick till dess tp nått sin VO2max. Var 15:e sekund registrerades tp:s HF, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) och respiratorisk kvot (RER) med hjälp av ett datoriserat syreupptagningssystem. Resultat Korrelationen var signifikant och hög (r = 0,89, p<0,0001) mellan utvecklad power på 5MPT och VO2max (l/min) och även mellan antalet vändor på 5MPT och VO2max (l/min) (r = 0,89, p<0,0001) på detta material av elitorienterare. Följande formler, baserade på resultaten från elitorienterarna, kan användas för att predicera VO2max efter genomfört 5MPT: VO2max  (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTVÄNDOR – 74,447) / 9,7668 Slutsats 5MPT uppvisar en stark korrelation med bestämd VO2max sett till power och/eller antalet genomförda vändor. Beräkningsformler för prediktion av VO2max har varit möjligt att beskriva. Se resultatdelen för andra resultat och samband mellan 5MPT och VO2max. / Abstract Aim The aim of this study was to investigate for elite orienteers the results in and the correlation between a so called 5-minutes-pyramid test (5MPT) and a specific maximum oxygen uptake test (VO2max) on a treadmill. The questions we asked ourselves were: Which correlation exists between 5MPT and a specific VO2max on the treadmill for elite orienteers? How would a comparison look like between measured and estimated VO2max? What is the reliability for the 5MPT? How would an equation look like that describe the correlation above? Method In the validity the study 16 elite orienteers (6 women and 10 men) aged 17 to 37 years participated. The two tests that have been carried out were the 5MPT and determined VO2max during running on a treadmill. The 5MPT is a 5-minute-shuttle test, in which the participant moves back and forth in a short interval (5.5 m) over boxes (highest height: 0.62) formed like a pyramid. Power in the pyramid test (5MPTPOWER) was calculated as the product of numbers of laps, body weight, gravity and highest box level divided by time. To determine VO2max the method running on a treadmill was performed. During the first minute the running speed was 8km/h (women)/10 km/h (men) without elevation. Each minute the velocity increased with 1 km/h. The elevation increased with 1 degree after the first minute and thereafter with 0,5 degrees/minute.  The test was finished when the participant had reached her VO2max. Every 15 second the participants heart rate, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) and RER, was registered by means of an online system. Results The correlation between the developed power of the 5MPT and measured VO2max (l/min) was high (r = 0.89, p<0,0001) and also between the number of laps in the 5MPT and measured VO2max (l/min) (r = 0.89, p < 0,0001). The following formulas can be used to predict VO2max after completed 5MPT: VO2max  (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTLAPS – 74,447) / 9,7668 Conclusions 5MPT show a strong correlation with VO2max determined in terms of power and/or the number of completed laps. Calculated formulas for prediction of VO2max have been possible to describe. See results section for other results and relationships between 5MPT and VO2max. / Maximal Aerobic Power versus Performance in Two Aerobic Endurance Tests among Young and Old Adults.Andersson E, Lundahl N, Wecke L, Lindblom I, Nilsson, J.

Existing ecotoxicity data for chemicals vary to a high extent between the environmental compartments water and sediment, since the evaluation of contaminants has historically focused on water exposition. Many anthropogenic chemicals and waste materials, including toxic organic and inorganic chemicals, adsorb to particulate matter and accumulate in sediments, and may thus be a threat to organisms living in the sediment. The invertebrates Chironomus riparius and Lumbriculus variegatus were selected as representatives of endobenthic living organisms. Acute toxicity tests, via water-only exposure, and sediment toxicity tests were conducted with the two endobenthic invertebrates. In sediment toxicity tests, organisms are mainly exposed to sediment- and particle-bound chemicals and dissolved chemical in the pore water. Toxicity data for algae, daphnids, and fish (via water-only exposure) are available for many substances, whereas the existing sediment toxicity data are rather rare. Thus, the interest arises to predict sediment toxicity for sediment-dwelling invertebrates from existing acute toxicity data of tests with water-only exposure. The main emphasis of this work was placed on one metal compound and seven organic chemicals. The objective of this study was fivefold: (1) develop methods and improve existing procedures on acute and sediment toxicity testing of the two invertebrates; (2) conduct both acute toxicity tests via water exposure and long-term sediment toxicity tests for the selected model substances to generate data for comparative discussion; (3) assess correlations among acute toxicity data of the organisms exposed via water-only and correlations among sediment toxicity data of the two endobenthic invertebrates for the eight tested chemicals; (4) assess possible forecasting for sediment toxicity from acute toxicity (via water-only exposure) and (5) assess exposure effects to determine the main exposure route. Acute toxicity data of the eight tested chemicals of D. magna significantly correlated with data of L. variegatus and C. riparius (p<0.05). However, a prediction of toxicity based on D. magna data bears high uncertainty, due to the small data set and high variation in sensitivity of the organisms. Existing sediment toxicity test methods were improved to meet the demand for artificial sediments containing organic matter that serves sufficiently as internal food source for the test organisms, and thus representing natural exposure conditions. However, the sediments that were used for the two organisms to test the selected model substances differed in sediment composition. Therefore, a sediment with the same sediment composition and the same water-to-sediment ratio for both invertebrates was developed, to have similar exposure conditions. In sediment toxicity tests, C. riparius was observed to be more sensitive than L. variegatus and no correlation was observed among data of the invertebrates. For the selected substances, lowest effect concentrations were observed for 3,4-dichloroaniline, whereas effect concentrations were the highest for benzo[a]pyrene. No correlations were found between the acute toxicity data of exposure via the water phase and sediment toxicity data, thus making a prediction of sediment toxicity data impossible. From analytical measurements of chemicals concentration in the compartments overlying, pore water, and bulk sediment, partition coefficients on sediment water partitioning were calculated. The highest partition coefficient ratios for sediment water partitioning were found for the high lipophilic organic substances 4,4-dichlorodiphenyltrichloroethan (DDT) and benzo[a]pyrene. Further, it was found that the main exposure routes in the 28-day sediment toxicity tests were not only chemical but species-dependent. As a result of very differing exposure routes for the tested chemicals and the absence of correlations from the acute to sediment toxicity data, sediment toxicity tests are necessary to assess the toxicity of chemicals on sediment inhabiting organisms. / In den meisten standardisierten ökotoxikologischen Untersuchungen zur Abschätzung des Gefährdungspotentials von Chemikalien für Gewässer erfolgt die Exposition der Organismen über die Wasserphase. Viele Schadstoffe, die in die aquatische Umwelt gelangen, adsorbieren aufgrund ihrer physikalisch-chemischen Eigenschaften an die Oberflächen von Schwebstoffen, sedimentieren und erreichen Sedimentkonzentrationen, die möglicherweise eine Gefahr für sedimentbewohnende Organismen darstellen. Im Rahmen dieser Arbeit wurden für benthische Invertebraten Testverfahren etabliert, bei denen eine Exposition der Organismen über das Sediment, hier hauptsächlich über die an ingestierte Sedimentbestandteile gebundene oder über die im Porenwasser gelöste Chemikalie (28-Tage Sedimenttoxizitätstest), und über dieWasserphase (Akuttoxizitätstest) erfolgte. Die Invertebraten Chironomus riparius und Lumbriculus variegatus wurden als typische Vertreter endobenthischer Organismen ausgewählt. Für viele Chemikalien liegen Daten zur akuten Toxizität für Algen, Daphnien und Fische für die Wasserexposition vor. Demgegenüber sind nur wenige Daten zur Toxizität für benthische Organismen weder mit einer Wasser- noch mit einer Sedimentexposition vorhanden. Als Modellsubstanzen wurden eine anorganische und sieben organische Substanzen für die Untersuchungen ausgewählt. Ziele dieser Arbeit waren: (1) die Entwicklung und Verbesserung von bestehenden Methoden zur Bestimmung der akuten Toxizität mitWasserexposition und der Sedimenttoxizität für die beiden Invertebraten; (2) die Durchführung der Tests mit den acht ausgewählten Modellsubstanzen zur vergleichenden Betrachtung; (3) die Beurteilung einer Korrelation der Daten zur Akuttoxizität innerhalb der verschiedenen Organismen mit Wasserexposition und einer Korrelation der Daten zwischen den beiden benthischen Organismen bei Sedimentexposition; (4) die Beurteilung einer Korrelation zwischen Daten der benthischen Invertebraten zur Akuttoxizität mit Wasserexposition und Sedimenttoxizität und (5) die Ermittlung und Bewertung der Expositionspfade. Die Akuttoxizitätsdaten von D. magna korrelieren significant (p<0.05) mit den Daten der beiden Invertebraten. Jedoch ist eine Vorhersage aufgrund des kleinen Datensatzes und der großen Unterschiede in der Empfindlichkeit der Arten abzulehnen. Um einer möglichst natürlichen Expositionssituation in Sedimenten zu entsprechen, wurden künstliche Sedimente mit interner Futterquelle, die auch mit der zu testenden Chemikalie kontaminiert wurde, entwickelt und für die Tests mit den Modellsubstanzen verwendet. Ein Nachteil war die unterschiedliche Sedimentzusammensetzung für die beiden Organismen. Um gleiche Expositionsbedingungen für beide Testorganismen zu gewährleisten, wurde ein artifizielles Sediment mit gleicher Zusammensetzung und gleichem Volumenverhältnis zwischen Sediment und Überstandswasser entwickelt. In den Sedimenttoxizitätstests reagierte C. riparius empfindlicher als L. variegatus. Die Effektkonzentrationen waren am niedrigsten für 3,4-Dichloraniline und am höchsten für Benzo[a]pyren. Die Korrelationen zwischen den Ergebnissen aus Akut- und Sedimenttoxizitstests waren nicht signifikant (p>0.05). Folglich läßt sich die Sedimenttoxizität nicht aus Daten zur akuten Toxizität mit Wasserexposition abschätzen. Aus den analytischen Messungen von Sediment-, Porenwasser- und Überstandswasserproben wurden die Koeffizienten für die Verteilung zwischen Sediment und Wasser berechnet. Für die stark lipophilen Stoffe, 4-Dichlorodiphenyltrichloroethan (DDT) und Benzo[a]pyren wurden die höchsten Koeffizienten errechnet. Weiterhin wurde festgestellt, daß die Hauptexpositionspfade in Sedimenttoxizitätstests einerseits von der Chemikalie und andererseits von der verwendeten Spezies abhängen. Aufgrund der Ergebnisse dieser Arbeit und der Tatsache, daß Sedimente “Senken” für viele Schadstoffe sind, müssen zur Erfassung und Bewertung des Gefährdungspotentials von Chemikalien gegenüber Sedimentbewohnern weiterhin Sedimenttoxizitätstests durchgeführt werden.

No description available.

Endocytosis is one of the most fundamental mechanisms by which the cell communicates with its surrounding. Specific signals are transduced through the cell membrane by a complex interplay between proteins and lipids. Clathrin depended endocytosis is one of important signalling pathways which leads to budding of the plasmalemma and a formation of endosomes. The FCHo2 is an essential protein at the initial stage of the this process. In is a membrane binding protein containing BAR (BIN, Amphiphysin, Rvs) domain which is responsible for a membrane binding. Although numerous valuable work on BAR proteins was published recently, the mechanistic description of a BAR domain functionality is missing. In present work we applied in vitro systems in order to gain knowledge about molecular basis of the activity of the FCHo2 BAR domain. In our studies we used supported lipid bilayers (SLBs) and lipid monolayers as s model membrane system. The experiments were carried out with a minimal number of components including the purified FCHo2 BAR domain. Using SLBs we showed that the BAR domain can bind to entirely flat bilayers. We also demonstrated that these interactions depend on the negatively charged lipid species incorporated in the membrane. We designed an assay which allows to quantify the membrane tubulation. We found out that the interaction of the FCHo2 BAR domain with the lipid membrane is concentration dependent. We showed that an area of the bilayer deformed by the protein depends on the amount of the used BAR domain. In order to study the relation between the mobility of lipids and the activity of FCHo2 BAR domain we designed a small-volume monolayer trough. The design of this micro-chamber allows for the implementation of the light microscopy. We demonstrated that the measured lipid diffusion in the monolayer by our new approach is in agreement with literature data. We carried out fluorescence correlation spectroscopy (FCS) experiments at different density of lipids at the water-air interface.We showed that the FCHo2 BAR domain binding affinity is proportional to the mean molecular area (MMA). We additionally demonstrated that the increased protein binding is correlated with the higher lipid mobility in the monolayer. Additionally, by curing out high-speed atomic force microscopy (hsAFM) we acquired the structural information about FCHo2 BAR domains orientation at the membrane with a high spatio-temporal resolution. Obtained data indicate the BAR domains interact witheach other by many different contact sites what results in a variety of protein orientations in a protein assemble.

Secret key generation from reciprocal multi-antenna channels is an interesting alternative to cryptographic key management in wireless systems without infrastructure access. In this work, we study the secret key rate for the basic source model with a MIMO channel. First, we derive an expression for the secret key rate under spatial correlation modelled by the Kronecker model and with spatial precoding at both communication nodes. Next, we analyze the result for uncorrelated antennas to understand the optimal precoding for this special case, which is equal power allocation. Then, the impact of correlation is characterized using Majorization theory. Surprisingly for small SNR, spatial correlation increases the secret key rate. For high SNR, the maximum secret key rate is achieved for uncorrelated antennas. The results indicate that a solid system design for reciprocal MIMO key generation is required to establish the secret key rate gains.

Conn., Yale Univ., Diss.--New Haven, 2004. / Kopie, ersch. im Verl. UMI, Ann Arbor, Mich. - Enth. 3 Beitr.

Bakgrund: Befolkningens hälsoutveckling följs ofta genom enkätundersökningar. Dessa har ofta med en generell fråga om självskattad hälsa, vilket har visat sig ha samband med såväl fysiska som psykiska faktorer. För enkätundersökningar riktade till ungdomar används ofta en fråga om självskattat mående. Det är dock inte empiriskt klarlagt vad självskattat mående hos ungdomar egentligen mäter. Syfte: Studien syftar till att undersöka i vilken utsträckning självskattat mående hos ungdomar mäter hälsorelaterad livskvalitet, där både positiva och negativa aspekter av hälsa ingår, positiv hälsa i form av positiv psykisk hälsa, psykisk ohälsa i form av symptom på depression/ångest, fysisk ohälsa gällande symptom på smärta/värk samt medicinska tillstånd i form av astma, födoämnesallergi, allergi, migrän och öronsus/tinnitus. Metod: En kvantitativ metod med tvärsnittsdesign användes med data från enkätundersökningen Liv och Hälsa Ung 2014, där 4047 elever från årskurs nio på högstadiet och årskurs två på gymnasiet i Västmanland inkluderades. Korrelationsanalyser genomfördes. Resultat: Självskattat mående mäter hälsorelaterad livskvalitet, positiv psykisk hälsa och psykisk ohälsa i måttlig utsträckning, smärta/värk i liten utsträckning och medicinska tillstånd i mycket liten utsträckning.  Slutsats: Självskattat mående mäter psykiska faktorer mer än fysiska faktorer. Självskattat mående mäter även hälsorelaterad livskvalitet i måttlig utsträckning, vilket motsvarar ett helhetsperspektiv på hälsa. Självskattat mående bland ungdomar är inte en adekvat indikator för fysisk ohälsa vilket bör tas i beaktande när denna fråga tolkas i befolkningsundersökningar. / Background: The health development of the population is often followed by questionnaires. These often include a general question of self rated health, which has been shown to be associated with both physical and mental factors. For questionnaires aimed at adolescents, a genereal question of self rated well-being is often used. However, it is not empirically clear what that question really measure. Aim: This study aims at investigating to which extent self rated well-being among adolescents measures health related quality of life, including both positive and negative aspects of health, positive health in terms of positive mental health, mental health in terms of symptoms of depression/anxiety, physical health complaints and medical conditions. Method: A quantitative method with a cross-sectional design was used with data from ”Survey of Adolescent Life in Vestmanland” (SALVe), 2014, which included 4047 students in grade 9 in elementary school and grade 2 in high school in Västmanland. Correlation analysis were used. Results: Self rated well-being is measuring health related quality of life, positive mental health and mental health to a moderate extent, physical complaints to a small extent and medical conditions to a very small extent. Conclusion: Self rated well-being measures mental factors more than physical factors. Self rated well-being also measures health-related quality of life to a moderate extent, which corresponds with a holistic perspective of health. Self rated well-being among adolescents is not an adequate indicator of physical complaints and medical conditions, which should be taken into consideration when the result of the question is interpreted in population surveys.

The objective of this study was to investigate the utilization of the diagnose-based Charlson Comorbidity Index (CCI) and the medication-based Rx-Risk Comorbidity Index on Swedish administrative data. Data was collected over a ten-year period from the National Patient Register and the National Prescribed Medication Register on 3609 respondents from the national public health survey 2018, aged 16-84 and registered in Stockholm County. The overall aim was to identify comorbid conditions in the study population; and to examine if the identified comorbidities differ between indices, based on subject characteristics such as age and gender. Moreover, the specific aim was to quantify correlation between the indices, as well as within indices over look-back periods of up to ten years. Among the study population, 13 % were identified with at least one comorbid condition through CCI, and 87 % had medications indicative of at least one condition covered by Rx-Risk. Both the original Charlson weights and updated weights by Quan were used to compute the comorbidity scores for CCI. Results showed that when CCI and Quan may have scored low, the Rx-Risk picked up more conditions. The Spearman rank correlation between CCI and Quan scores resulted in relatively high correlation with a coefficient of 0.82 (p-value < 0.05) over look-back periods of 2, 5 and 10 years. Moreover, the correlation between CCI and Rx-Risk was fairly low over all look-back periods with a correlation coefficient of 0.34 (p-value < 0.05) at most. The within-correlation showed that CCI identified much of the comorbidity between the one- and two-year look-back periods, whilst Rx-Risk identified much comorbidity within the one-year look-back period. The overall implications of the presented results are that a utilization of Charlson index and Rx-Risk is likely to capture comorbid conditions in different health care settings, and thus expected correlation is to be of modest level between the two indices. The research question of interest should therefore determine which index is favorable when assessment of comorbidity is desired.