Imbalance p values for baseline covariates in randomized controlled trials: a last resort for the use of p values? A pro and contra debate

Background

Results of randomized controlled trials (RCTs) are usually accompanied by a table that compares covariates between the study groups at baseline. Sometimes, the investigators report p values for imbalanced covariates. The aim of this debate is to illustrate the pro and contra of the use of these p values in RCTs.

Pro

Low p values can be a sign of biased or fraudulent randomization and can be used as a warning sign. They can be considered as a screening tool with low positive-predictive value. Low p values should prompt us to ask for the reasons and for potential consequences, especially in combination with hints of methodological problems.

Contra

A fair randomization produces the expectation that the distribution of p values follows a flat distribution. It does not produce an expectation related to a single p value. The distribution of p values in RCTs can be influenced by the correlation among covariates, differential misclassification or differential mismeasurement of baseline covariates. Given only a small number of reported p values in the reports of RCTs, judging whether the realized p value distribution is, indeed, a flat distribution becomes difficult. If p values ≤0.005 or ≥0.995 were used as a sign of alarm, the false-positive rate would be 5.0% if randomization was done correctly, and five p values per RCT were reported.

Conclusion

Use of a low p value as a warning sign that randomization is potentially biased can be considered a vague heuristic. The authors of this debate are obviously more or less enthusiastic with this heuristic and differ in the consequences they propose.

The association between geographic location and incidence of Merkel cell carcinoma in comparison to melanoma: An international assessment

AIM

The aim of this article was to provide worldwide, population-based incidence rates for Merkel cell carcinoma (MCC).

METHODS

We included 11,576 cases from 20 countries for time trend analyses (1990-2007) and 11,028 cases (2.5 billion person-years) from 21 countries for the period 2003-2007 extracted from Cancer Incidence in Five Continents. We computed age-standardised incidence rates (World Standard population) per million person years and sex ratios of these rates. We estimated annual percentage changes (EAPCs) of the incidence and studied the association between geographic latitude and MCC incidence. We examined the body site distribution of MCC.

FINDINGS

In the majority of populations, the incidence has increased over time (EAPC, men 2.0-21.0%; women 1.6-27.2%). Rate differences between 1995 and 2007 were typically small (men: 0.8-2.2; women: 0.2-1.7). The incidence was relatively stable in some populations (men: U.S. blacks, Japan, Norway, Denmark; women: Denmark, Norway, Sweden). Incidences from 2003 to 2007 were highest in Australia, New Zealand, the United States and Israel among men and in New Zealand, Australia, Ireland and the Netherlands among women. The incidence of MCC and melanoma among white non-Hispanic males in North America was positively associated with living closer to the equator. The proportion of MCC on the head was higher with advanced age. The head was a less likely primary site among blacks as compared with any other ethnicity.

INTERPRETATION

Several countries showed increases in MCC incidence among white non-Hispanics over time. Latitude closer to the equator was associated with the MCC incidence in North American men, but barely in women, possibly due to occupational sunlight exposure patterns.

Epidemiology, biology and therapy of Merkel cell carcinoma: conclusions from the EU project IMMOMEC

Merkel cell carcinoma (MCC) is a highly aggressive, often lethal neuroendocrine cancer. Its carcinogenesis may be either caused by the clonal integration of the Merkel cell polyomavirus into the host genome or by UV-induced mutations. Notably, virally-encoded oncoproteins and UV-induced mutations affect comparable signaling pathways such as RB restriction of cell cycle progression or p53 inactivation. Despite its low incidence, MCC recently received much attention based on its exquisite immunogenicity and the resulting major success of immune modulating therapies. Here, we summarize current knowledge on epidemiology, biology and therapy of MCC as conclusion of the project 'Immune Modulating strategies for treatment of Merkel Cell Carcinoma', which was funded over a 5-year period by the European Commission to investigate innovative immunotherapies for MCC.

Sleep characteristics and progression of coronary artery calcification: Results from the Heinz Nixdorf Recall cohort study

BACKGROUND AND AIMS

Sleep characteristics are associated with incident cardiovascular diseases (CVD), but there is a lack of studies on the association between sleep characteristics and incidence/progression of coronary artery calcification (CAC).

METHODS

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany, CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. In an analysis set of 3043 subjects (age at baseline 45-74 years; 47% men), we fitted logistic and linear regression models to assess associations between self-rated sleep characteristics (nocturnal and total sleep duration; napping; various sleep disorders) and CAC incidence/CAC progression. Progression was measured as 5-year progression factor, as categories of absolute CAC change, and additionally characterized as rapid or slow compared to an extrapolation of baseline CAC values.

RESULTS

We observed barely any association between sleep characteristics and CAC progression regardless of the chosen statistical approach; associations between sleep and CAC incidence were slightly larger, e.g., the geometric mean of the 5-year CAC progression factor was 6.8% (95% confidence interval: -9.5; 25.9) larger for ≤5 h, 2.9% (-7.3; 14.3) larger for 5.1-6.9 h and 7.1% (-2.4; 15.7) smaller for ≥7.5 h total sleep compared to 7- <7.5 h total sleep. For subjects with any regular sleep disorder, the geometric mean of the 5-year CAC progression was 3.5% (-4.7; 11.2) smaller compared to subjects without any regular sleep disorder.

CONCLUSIONS

In this German cohort study, sleep characteristics were barely associated with CAC progression.

Bonner Venenstudie der Deutschen Gesellschaft für Phlebologie

Ziel: Die Bonner Venenstudie zur Frage der Häufigkeit und Ausprägung von chronischen Venenkrankheiten in der städtischen und ländlichen deutschen Wohnbevölkerung im Alter von 18-79 Jahren fand zwischen dem 13. 11. 2000 und 15. 3. 2002 statt. Es nahmen insgesamt 3072 Probanden teil, die Response-Proportion lag insgesamt bei 59%. Ergebnisse: Eine Beinschwellung in der Anamnese trat bei jedem 6. Mann (16,2%) und bei nahezu jeder 2. Frau (42,1%) auf. Eine kurz zurückliegende ein- oder beidseitige Beinschwellung in den letzten vier Wochen gab jeder 6. Teilnehmer an. Dies entspricht 14,8% (7,9% der Männer, 20,2% der Frauen). Für Gefäßerkrankungen typische Beinbeschwerden innerhalb der letzten vier Wochen gab insgesamt jeder 2. der Probanden (56,4%) an. Bei der Beurteilung der klinischen Ausprägung gemäß der CEAP-Klassifikation fällt auf, dass lediglich 9,6% der Probanden keinerlei Venenveränderungen aufweisen. Bei 59% bestehen isoliert Teleangiektasien oder retikuläre Venen, bei 14,3% Krampfadern (C2) ohne weitere Zeichen einer chronischen venösen Insuffizienz. Auffällig ist, dass bei 13,4% ein prätibiales Ödem im Rahmen von Venenveränderungen zum Untersuchungszeitpunkt vorlag. Demgegenüber liegt die Zahl der fortgeschrittenen Zeichen der chronischen venösen Insuffizienz bei 3,3%. Die Häufigkeit des floriden oder abgeheilten Ulcus cruris lag bei 0,7%. Schlussfolgerungen: Jeder 6. Mann und jede 5. Frau hat somit chronische Veneninsuffizienz (C3–C6). Die Zahlen zeigen, dass Venenkrankheiten insgesamt nach wie vor eine hohe Prävalenz aufweisen, dass aber die schweren Ausprägungen der chronischen venösen Insuffizienz in den vergangenen 20 Jahren zurückgegangen sind.

Prevalence of Stemmer's sign in the general population

Lymphoedema is a disease frequently diagnosed in vascular departments, its origin being primary or secondary after cellulitis or cancer treatment. The prevalence of lower extremity lymphoedema in the general population is largely unknown. The aim of this article is to describe the prevalence of Stemmer's sign as a diagnostic criterium for lymphoedema in an unselected adult German population. Methods: The population for this cross-sectional study was recruited from November 2000 through March 2002 from the general population of the city of Bonn and two surrounding rural communities. 3072 individuals (1145 rural and 1927 urban) could be enrolled in the study. The results of the clinical examination were categorized in four groups: grade 0 normal skin fold at the dorsum of the second toe, grade 1 skin fold enlarged measuring 0.5–1 cm, grade 2 the skin fold >1 cm and grade 3 >1 cm with severe induration or papillomatosis. Results: Among 3055 out of 3072 subjects information on all variables were available. In 15.9% of the population a positive Stemmer sign was found with a slightly higher overall prevalence in women. Most of this group presented as grade 1 Stemmer's sign (14.1%). The more severe grades 2 and 3 were present in 1.8 % of the study population with no clear difference between sexes. We observed a considerably higher prevalence of Stemmer's sign of all grades in the urban population. The prevalence of Stemmer's sign increased with age from 3.2% up to 35.9% in the 70–79 year old population. Prevalence of positive Stemmer's sign was also higher in higher C-stages of the CEAP classification (5.8% in C0 to 100% in C6). Conclusions: The prevalence of lymphoedema in the general population represented by grade 2–3 Stemmer's sign in 1.8% and grade 1 Stemmer's sign in 14% is high. Women have a slightly higher prevalence of positive Stemmer's sign than men. The prevalence of positive Stemmer's sign is associated with age and chronic venous insufficiency.

Prevalence and acceptance of therapy with medical compression stockings

The aim of this study was to assess the prevalence of use of medical compression stockings (MCS) in the general adult population in Germany, to comment the indications for which MCS therapy has been described and the patients’ experience with it. Methods: The survey is based on the Bonn Vein Study. The population of this cross-sectional study was randomly recruited between November 2000 and March 2002 from the registers of residents of the city of Bonn and two rural townships in the area. In total, 3.072 men and women were included in the trial. In addition to clinical examination and duplex-ultrasound, participants were asked whether any phlebological treatment had been carried out due to a leg disorder or disease.. If compression stockings had been worn, we asked for details such as compression class and length of stockings, wearing time, effectiveness, and recognition. Results: In total, 22.9% of people providing information (12.7% of male, 31.0% of female) mentioned having received a specific phlebological treatment in the past. Therapy with compression stockings had the highest prevalence with 14.6% in the general population (7.5% of males, 20.3% of females). The mean age at the first prescription was 45.5 years (SD = 14.3 years). With increasing severity of venous disease, as rated according to the CEAP classification, the prevalence increased from 1% in C0 patients to 82% in C5/C6 patients. Of 450 participants who had used compression stockings in the past, 309 (68.6%) did not wear CS at the time of the survey. The remainder had generally been wearing them on five or more days per week (73.0%) for 8 or more hours per day (89.4%). On average, 71.3% of the participants said that the disease for which MCS were prescribed, had improved as a result of MCS therapy. Improvement concerned a reduction of sensations of swelling (84.2%), of heaviness (89.4%), leg pain after long periods of standing (60.9), and tension in the legs (78.9).

[Mistakes and Drawbacks in German Newspaper Articles on Epidemiologic Studies: "Meat Consumption and Colorectal Cancer" as an Example]

BACKGROUND

Results of epidemiologic studies are often reported in the media because they are of vital interest for many people. Using the example of meat consumption and colorectal cancer, we investigated whether results of epidemiologic studies are reported in an understandable and correct manner in German newspapers and magazines.

METHODS

We gathered all articles published in 13 selected German newspapers and magazines that referred to a press release on meat consumption and colorectal cancer issued by the International Agency for Research on Cancer (IARC) on October 26th 2015. We analyzed these articles with regard to comprehensibility and correctness, and assessed the criteria used by the newspapers and magazines to judge the credibility of the research results.

RESULTS

In the IARC press release, relative risks were used ("The experts concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18%"), which 11 of 13 print media adopted. However, this wording may be misinterpreted by many readers as an increase of 18 percentage points, indicating that absolute risks should be preferred to relative risks in the newspapers and magazines. Only 6 print media reported absolute risks. 5 print media misleadingly reported thresholds for safe meat consumption. Other mistakes were vague descriptions of the index group (e.g. "excessive meat consumption" without specifying the exact amount (g/day)) and the reference group, and lack of time periods for which risks were estimated. To judge the credibility of the research on meat consumption and cancer risk, criteria for the quality of epidemiologic studies such as confounding and precision in the assessment of meat consumption were hardly taken into account.

CONCLUSION

Scientific institutions should attach more importance to an understandable presentation of measures of occurrence, measures of effects and important sources of bias in press releases. In the case of meat consumption and colorectal cancer, a higher quality of the press release by the IARC - in particular, reporting absolute instead of relative risks - would probably have led to less misleading publications in the print media.

Impact of the estimation equation for GFR on population-based prevalence estimates of kidney dysfunction

Background

Estimating equations are recommended by clinical guidelines as the preferred method for assessment of glomerular filtration rate (GFR). The aim of the study was to compare population-based prevalence estimates of decreased kidney function in Germany defined by an estimated GFR (eGFR) <60 ml/min/1.73m² using different equations.

Methods

The study included 7001 participants of the German Health Interview and Examination Survey for Adults 2008–2011 (DEGS1) for whom GFR was estimated using the Modification of Diet in Renal Disease study equation (MDRD), the revised Lund-Malmö equation (LM), the Full Age Spectrum creatinine equation (FAScre), the Chronic Kidney Disease Epidemiology Collaboration equations with creatinine and cystatin C (CKD-EPIcrecys), with creatinine (CKD-EPIcre) and with cystatin C (CKD-EPIcys). Bland-Altman plots were used to evaluate the agreement between the equations.

Results

Prevalence estimates of decreased kidney function were: 2.1% (CKD-EPIcys), 2.3% (CKD-EPIcrecys), 3.8% (CKD-EPIcre), 5.0% (MDRD), 6.0% (LM) and 6.9% (FAScre). The systematic differences between the equations were smaller by comparing either equations that include serum cystatin C or equations that include serum creatinine alone and increased considerably by increasing eGFR.

Conclusions

Prevalence estimates of decreased kidney function vary considerably according to the equation used for estimating GFR. Equations that include serum cystatin C provide lower prevalence estimates if compared with equations based on serum creatinine alone. However, the analysis of the agreement between the equations according to eGFR provides evidence that the equations may be used interchangeably among persons with pronounced decreased kidney function. The study illustrates the implications of the choice of the estimating equation in an epidemiological setting.

Electronic supplementary material

The online version of this article (10.1186/s12882-017-0749-5) contains supplementary material, which is available to authorized users.

Value of Progression of Coronary Artery Calcification for Risk Prediction of Coronary and Cardiovascular Events: Result of the HNR Study (Heinz Nixdorf Recall)

Supplemental Digital Content is available in the text.

Background:

Computed tomography (CT) allows estimation of coronary artery calcium (CAC) progression. We evaluated several progression algorithms in our unselected, population-based cohort for risk prediction of coronary and cardiovascular events.

Methods:

In 3281 participants (45–74 years of age), free from cardiovascular disease until the second visit, risk factors, and CTs at baseline (b) and after a mean of 5.1 years (5y) were measured. Hard coronary and cardiovascular events, and total cardiovascular events including revascularization, as well, were recorded during a follow-up time of 7.8±2.2 years after the second CT. The added predictive value of 10 CAC progression algorithms on top of risk factors including baseline CAC was evaluated by using survival analysis, C-statistics, net reclassification improvement, and integrated discrimination index. A subgroup analysis of risk in CAC categories was performed.

Results:

We observed 85 (2.6%) hard coronary, 161 (4.9%) hard cardiovascular, and 241 (7.3%) total cardiovascular events. Absolute CAC progression was higher with versus without subsequent coronary events (median, 115 [Q1–Q3, 23–360] versus 8 [0–83], P<0.0001; similar for hard/total cardiovascular events). Some progression algorithms added to the predictive value of baseline CT and risk assessment in terms of C-statistic or integrated discrimination index, especially for total cardiovascular events. However, CAC progression did not improve models including CAC_5y and 5-year risk factors. An excellent prognosis was found for 921 participants with double-zero CAC_b=CAC_5y=0 (10-year coronary and hard/total cardiovascular risk: 1.4%, 2.0%, and 2.8%), which was for participants with incident CAC 1.8%, 3.8%, and 6.6%, respectively. When CAC_b progressed from 1 to 399 to CAC_5y≥400, coronary and total cardiovascular risk were nearly 2-fold in comparison with subjects who remained below CAC_5y=400. Participants with CAC_b≥400 had high rates of hard coronary and hard/total cardiovascular events (10-year risk: 12.0%, 13.5%, and 30.9%, respectively).

Conclusions:

CAC progression is associated with coronary and cardiovascular event rates, but adds only weakly to risk prediction. What counts is the most recent CAC value and risk factor assessment. Therefore, a repeat scan >5 years after the first scan may be of additional value, except when a double-zero CT scan is present or when the subjects are already at high risk.

[Medical Progress ans Public Health - Results of the Working Group 4 of the Forum Future Public Health, Berlin]

Medical actions that have been shown to be beneficial in individual studies may be associated with a negative benefit-harm balance at the population level due to oversupply or undersupply. Therefore, structured dialogues among basic researchers, clinicians and public health researchers are needed to generate relevant public health questions in relation to medical actions and to undertake research projects that answer these questions. For this purpose, more structured PhD programs in public health are required. Implementation barriers for evidence-based medical actions in the population need to be identified and tailored interventions to reduce these barriers need to be developed and evaluated.

Aortic Calcification Onset and Progression: Association With the Development of Coronary Atherosclerosis

Background

Thoracic aortic calcification (TAC) and coronary artery calcification (CAC) are markers of subclinical atherosclerosis and are associated with incident major cardiovascular events. We investigated major determinants for incidence and progression of TAC and the association between TAC and CAC incidence and progression.

Methods and Results

In a population‐based cohort study, 3270 participants (aged 45–74 years, 53.1% women) received cardiac computed tomography at baseline and after a mean follow‐up of 5.1±0.3 years for quantification of calcification of the ascending (ATAC) and descending thoracic aorta (DTAC) and CAC. Multivariable relative risk regression analysis was used to investigate associations of cardiovascular risk factors with incident TAC, of baseline TAC with incident CAC, and of baseline CAC with incident TAC. Of 1243 participants with baseline TAC of 0, 517 (41.6%) revealed incident TAC after 5 years. Incidence of descending TAC was higher (34.5%) than ascending TAC (23.3%). Incident TAC after 5 years was associated with age (relative risk 1.26 [95% CI 1.21–1.33], per 5 years), blood pressure (relative risk 1.06 [95% CI 1.03–1.10], per 10 mm Hg), low‐density lipoprotein cholesterol (relative risk 1.08 [95% CI 1.04–1.12], per 20 mg/dL), and smoking (relative risk 1.28 [95% CI 1.07–1.53]). Among the 1185 participants without CAC at baseline, the risk of developing CAC was 28.3% when baseline TAC was present compared with 22.2% among those without baseline TAC (excess risk 6.1% [95% CI 1.2–11.0%]). The point estimate of excess risk for incident CAC was higher for ascending TAC (10.8% [95% CI 4.8–16.7%]) and low for descending TAC (1.8% [95% CI −3.2% to 6.7%]). Excess risk for developing ascending and descending TAC with present baseline CAC was 16.4% (95% CI 12.7–20.0%) and 15.6% (95% CI 10.8–20.4%), respectively.

Conclusion

TAC and CAC share similar major determinants for incident calcification. Participants with TAC, especially ascending TAC, are at elevated risk for development of CAC.

Perceived risk of diabetes seriously underestimates actual diabetes risk: The KORA FF4 study

OBJECTIVE

Early detection of diabetes and prediabetic states is beneficial for patients, but may be delayed by patients´ being overly optimistic about their own health. Therefore, we assessed how persons without known diabetes perceive their risk of having or developing diabetes, and we identified factors associated with perception of diabetes risk.

RESEARCH DESIGN AND METHODS

1,953 participants without previously known diabetes from the population-based, German KORA FF4 Study (59.1 years, 47.8% men) had an oral glucose tolerance test. They estimated their probability of having undiagnosed diabetes mellitus (UDM) on a six category scale, and assessed whether they were at risk of developing diabetes in the future. We cross-tabulated glycemic status with risk perception, and fitted robust Poisson regression models to identify determinants of diabetes risk perception.

RESULTS

74% (95% CI: 65-82) of persons with UDM believed that their probability of having undetected diabetes was low or very low. 72% (95% CI: 69-75) of persons with prediabetes believed that they were not at risk of developing diabetes. In people with prediabetes, seeing oneself at risk of diabetes was associated with self-rated poor general health (prevalence ratio (PR) = 3.1 (95% CI: 1.4-6.8), parental diabetes (PR = 2.6, 1.9-3.4), high educational level (PR = 1.9 (1.4-2.5)), lower age (PR = 0.7, 0.6-0.8, per 1 standard deviation increase), female sex (PR = 1.2, 0.9-1.5) and obesity (PR = 1.5, 1.2-2.0).

CONCLUSIONS

People with undiagnosed diabetes or prediabetes considerably underestimate their probability of having or developing diabetes. Contrary to associations with actual diabetes risk, perceived diabetes risk was lower in men, lower educated and older persons.

Clinical management of unruptured intracranial aneurysm in Germany: a nationwide observational study over a 5-year period (2005-2009)

OBJECTIVES

Our aim was to provide nationwide age-standardised rates (ASR) on the usage of endovascular coiling and neurosurgical clipping for unruptured intracranial aneurysm (UIA) treatment in Germany.

SETTING

Nationwide observational study using the Diagnosis-Related-Groups (DRG) statistics for the years 2005-2009 (overall 83 million hospitalisations).

PARTICIPANTS

From 2005 to 2009, overall 39 155 hospitalisations with a diagnosis of UIA occurred in Germany.

PRIMARY OUTCOME MEASURES

Age-specific and age-standardised hospitalisation rates for UIA with the midyear population of Germany in 2007 as the standard.

RESULTS

Of the 10 221 hospitalisations with UIA during the observation period, 6098 (59.7%) and 4123 (40.3%) included coiling and clipping, respectively. Overall hospitalisation rates for UIA increased by 39.5% (95% CI 24.7% to 56.0%) and 50.4% (95% CI 39.6% to 62.1%) among men and women, respectively. In 2005, the ASR per 100 000 person years for coiling was 0.7 (95% CI 0.62 to 0.78) for men and 1.7 (95% CI 1.58 to 1.82) for women. In 2009, the ASR was 1.0 (95% CI 0.90 to 1.10) and 2.4 (95% CI 2.24 to 2.56), respectively. Similarly, the ASR for clipping in 2005 amounted to 0.6 (95% CI 0.52 to 0.68) for men and 1.1 (95% CI 1.00 to 1.20) for women. These rates increased in 2009 to 0.8 (95% CI 0.72 to 0.88) and 1.7 (95% CI 1.58 to 1.82), respectively. We observed a marked geographical variation of ASR for coiling and less pronounced for clipping. For the federal state of Saarland, the ASR for coiling was 5.64 (95% CI 4.76 to 6.52) compared with 0.68 (95% CI 0.48 to 0.88; per 100 000 person years) in Saxony-Anhalt, whereas, ASR for clipping were highest in Rhineland-Palatinate (2.48, 95% CI 2.17 to 4.75) and lowest in Saxony-Anhalt (0.52, 95% CI 0.34 to 0.70).

CONCLUSIONS

To the best of our knowledge, we presented the first representative, nationwide analysis of the clinical management of UIA in Germany. The ASR increased markedly and showed substantial geographical variation among federal states for all treatment modalities during the observation period.

Progression of coronary artery calcification is stronger in poorly than in well controlled diabetes: Results from the Heinz Nixdorf Recall Study

AIM

To assess associations between HbA1c and progression of coronary artery calcification (CAC) in persons with and without diabetes.

METHODS

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany (N=3453, aged 45-74years), CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. At baseline, participants were divided into five groups: poorly (HbA1c≥7.0%) and well (HbA1c<7.0%) controlled previously known diabetes (group I/II); no previously known diabetes with HbA1c ≥6.5% (group III), HbA1c 5.7-6.4% (group IV), and HbA1c <5.7% (group V). We fitted linear, logistic and robust Poisson regression models to assess associations between diabetes group and PF₅ (factor by which CAC after 5-year follow-up is larger than baseline CAC), and categories of CAC change, respectively.

RESULTS

Relative to group V, adjusted percentage increase of the geometric mean of PF₅ (95% CI) was: 69.1% (33.9%;113.6%), 15.4% (-5.6%;41.1%), -4.1% (-22.2%;18.2%), 4.2% (-5.4%;14.8%) for groups I-IV, respectively. The corresponding odds ratios for annual CAC increase ≥100 Agatston units (reference: <10) were 10.0 (4.8;20.6), 4.0 (2.1;7.6), 1.5 (0.7;3.2), and 1.1 (0.7;1.8).

CONCLUSIONS

In known diabetes, CAC progression was stronger in poor diabetes control. For newly detected diabetes diagnosed by HbA1c ≥6.5%, associations with CAC progression were weak.

Lung Cancer Screening Using Low Dose CT Scanning in Germany. Extrapolation of results from the National Lung Screening Trial

BACKGROUND

It is now debated whether the screening of heavy smokers for lung cancer with low dose computed tomography (low dose CT) might lower their mortality due to lung cancer. We use data from the National Lung Screening Trial (NLST) in the USA to predict the likely effects of such screening in Germany.

METHODS

The number of heavy smokers aged 55-74 in Germany was extrapolated from survey data obtained by the Robert Koch Institute. Published data from the NLST were then used to estimate the likely effects of low dose CT screening of heavy smokers in Germany.

RESULTS

If low dose CT screening were performed on 50% of the heavy smokers in Germany aged 55-74, an estimated 1 329 506 persons would undergo such screening. If the screening were repeated annually, then, over three years, 916 918 screening CTs would reveal suspect lesions, and the diagnosis of lung cancer would be confirmed thereafter in 32 826 persons. At least one positive test result in three years would be obtained in 39.1% of the participants (519 837 persons). 4155 deaths from lung cancer would be prevented over 6.5 years, and the number of persons aged 55-74 who die of lung cancer in Germany would fall by 2.6%. 12 449 persons would have at least one complication, and 1074 persons would die in the 60 days following screening.

CONCLUSION

The screening of heavy smokers for lung cancer can lower their risk of dying of lung cancer by 20% in relative terms, corresponding to an absolute risk reduction of 0.3 percentage points. These figures can provide the background for a critical discussion of the putative utility of this type of screening in Germany.

Intraobserver Agreement on Histopathologic Evaluations of Core Breast Biopsies

The number of performed core biopsies of the breast as diagnostic workup is increasing in many European countries. We measured the intraobserver variability in pathological assessment of breast core biopsies. Furthermore, we studied potential modifiers of agreement between the assessments. Two hundred and fifty-six breast biopsies were evaluated twice in a blinded fashion by two pathologists. We calculated the observed and the chance-corrected (weighted) intraobserver agreement (kappa) using the B-categorization scheme (B1: normal or not interpretable, B2: benign, B3: benign but of uncertain biological potential, B4: suspicious of malignancy, B5: malignant). The observed agreement between the first and the second assessments were 0.80 (95% CI: 0.75-0.85) for pathologist 1 and 0.81 (95% CI: 0.76-0.86) for pathologist 2. The chance-corrected agreements were 0.85 (95% CI: 0.80-0.89) and 0.81 (95% CI: 0.76-0.87), respectively. The most frequent disagreement was between B1 and B2 for pathologist 1 (N = 34 out of 50 disagreements, 68%) and between B2 and B3 for pathologist 2 (N = 23 out of 48 disagreements, 48%). Our study shows that the chance-corrected agreement between the histopathological evaluations of breast biopsies based on the B-categorization scheme is almost perfect. The level of agreement is modified by biopsy technique and by the level of suspicion of the mammographic lesion.

[Public Health: Setting Goals, Establishing Structures and Improving Health for All]

Public health is a population- and system-based approach that is needed to improve the health of societies and to decrease health inequalities. In the face of global challenges, the public health approach is essential. In Germany, the importance of public health is only partly reflected by its institutions and institutional arrangements. This applies equally to research, teaching and training, as well as to the public health service. Furthermore, the public health perspective is not sufficiently considered in cross-sectional topics that are relevant for health.There have been several initiatives to overcome structural deficits which can partly be traced back to historical circumstances. The White Paper presented here should encourage discussions about future policy options in public health. The authors represent public health in practice, research, and teaching in Germany.