Assessing how routes to diagnosis vary by the age of patients with cancer: a nationwide register-based cohort study in Denmark.

BACKGROUND: Older patients with cancer have poorer prognosis compared to younger patients. Moreover, prognosis is related to how cancer is identified, and where in the healthcare system patients present, i.e. routes to diagnosis (RtD). We investigated whether RtD varied by patients' age. METHODS: This population-based national cohort study used Danish registry data. Patients were categorized into age groups and eight mutually exclusive RtD. We employed multinomial logistic regressions adjusted for sex, region, diagnosis year, cohabitation, education, income, immigration status and comorbidities. Screened and non-screened patients were analysed separately. RESULTS: The study included 137,876 patients. Both younger and older patients with cancer were less likely to get diagnosed after a cancer patient pathways referral from primary care physician compared to middle-aged patients. Older patients were more likely to get diagnosed via unplanned admission, death certificate only, and outpatient admission compared to younger patients. The patterns were similar across comorbidity levels. CONCLUSIONS: RtD varied by age groups, and middle-aged patients were the most likely to get diagnosed after cancer patient pathways with referral from primary care. Emphasis should be put on raising clinicians' awareness of cancer being the underlying cause of symptoms in both younger patients and in older patients.

Strong association between cervical and breast cancer screening behaviour among Danish women; A register-based cohort study.

High coverage is essential for the effectiveness of national screening programmes. Identifying non-screeners across different screening programmes may help inform strategies to improve uptake. This study aims to analyse the association between previous cervical cancer screening (CCS) coverage and participation in breast cancer screening (BCS). This historical register-based cohort study included 91,787 Danish women aged 50-64 years who were invited to participate in the first organised round of BCS in the Central Denmark Region (CDR) in 2008-09. CCS coverage was defined as having a smear registered in the 5 1/2 years preceding the BCS, and BCS participants were divided into participants and non-participants and further categorised as active non-participants (ANP) if they cancelled and passive non-participants (PNP) if they abstained from the appointment. Of all 91,787 women included in the study, 62,391 (68%) were covered both by CCS and participated in BCS. Women not covered by CCS were more likely to be non-participants in BCS than women covered by CCS (PRRadjusted = 2.80, 95% CI: 2.68-2.93). Both PNP (PRRadjusted = 3.99, 95% CI: 3.80-4.19) and ANP (PRRadjusted = 2.50, 95% CI: 2.34-2.68) were more likely not to be covered by the CCS. In conclusion, non-coverage by CCS was strongly associated with nonparticipation in BCS. Specific groups of women only participated in one screening programme. To increase uptake, future interventions may specifically target these groups.

Impact of severe mental illness on cancer stage at diagnosis and subsequent mortality: A population-based register study.

BACKGROUND: Excess mortality in individuals with severe mental illness (SMI) is often explained by physical comorbidity and suboptimal healthcare. Cancer is a prevalent cause of death, and tumour stage at diagnosis is a strong predictor of mortality. We aimed to study cancer incidence, disease stage at diagnosis and subsequent mortality in individuals with SMI compared to individuals without SMI. METHODS: The entire Danish population was followed in 1978-2013 using nationwide registries. Cancer incidence and subsequent mortality stratified by disease stage were compared in individuals with and without SMI. Cox regression was used to estimate incidence rate ratios (IRR) and mortality rate ratios (MRR). Cancer was examined overall and grouped by major aetiological factors. RESULTS: The overall cancer incidence rate was lower in males with SMI than in males without SMI; IRR = 0.89 (95% CI: 0.85-0.94), but rates were similar in females with SMI and without SMI; IRR = 1.03 (95% CI: 0.99-1.07). The overall mortality rate was higher in individuals with SMI than those without; MRR = 1.56 (95% CI: 1.48-1.64) for males and MRR = 1.49 (95% CI: 1.43-1.56) for females. Incidence rates and mortality rates showed similar estimates when stratified by tumour stage and aetiology. CONCLUSIONS: We found lower cancer incidence in males with SMI compared to males without SMI and similar incidence in the two groups of women. Higher subsequent mortality was found in both sexes with SMI. The excess mortality was not explained by more advanced stages of cancer; future studies should evaluate the effect of cancer treatment and rehabilitation.

Evidence of advanced stage colorectal cancer with longer diagnostic intervals: a pooled analysis of seven primary care cohorts comprising 11 720 patients in five countries.

BACKGROUND: The benefits from expedited diagnosis of symptomatic cancer are uncertain. We aimed to analyse the relationship between stage of colorectal cancer (CRC) and the primary and specialist care components of the diagnostic interval. METHODS: We identified seven independent data sets from population-based studies in Scotland, England, Canada, Denmark and Spain during 1997-2010 with a total of 11 720 newly diagnosed CRC patients, who had initially presented with symptoms to a primary care physician. Data were extracted from patient records, registries, audits and questionnaires, respectively. Data sets were required to hold information on dates in the diagnostic interval (defined as the time from the first presentation of symptoms in primary care until the date of diagnosis), symptoms at first presentation in primary care, route of referral, gender, age and histologically confirmed stage. We carried out reanalysis of all individual data sets and, using the same method, analysed a pooled individual patient data set. RESULTS: The association between intervals and stage was similar in the individual and combined data set. There was a statistically significant convex (∩-shaped) association between primary care interval and diagnosis of advanced (i.e., distant or regional) rather than localised CRC (P=0.004), with odds beginning to increase from the first day on and peaking at 90 days. For specialist care, we saw an opposite and statistically significant concave (∪-shaped) association, with a trough at 60 days, between the interval and diagnosis of advanced CRC (P<0.001). CONCLUSIONS: This study provides evidence that longer diagnostic intervals are associated with more advanced CRC. Furthermore, the study cannot define a specific 'safe' waiting time as the length of the primary care interval appears to have negative impact from day one.

Characteristics of symptomatic men with testicular microlithiasis - A Danish cross-sectional questionnaire study.

Testicular microlithiasis (TML) is an incidental finding at ultrasonography of the scrotum. A link between testicular microlithiasis and testicular cancer has been suggested. However, the majority of studies are retrospective using ultrasonography with minor data on health status and life style characteristics. Our objective was to investigate if lifestyle and health are associated with TML. In 2014, we conducted a self-administered questionnaire survey including 1538 men, who all due to testicular/scrotal symptoms had an ultrasound investigation of the scrotum during 2004-2013. The men were divided into men with TML and men without. The 23-items questionnaire included items on age, height, weight, lifestyle (alcohol consumptions, smoking habits, workload, exercise and food), previous diseases in the testicles, pain and consumption of analgesics. The prevalence of TML was 12.8%. Overall, lifestyle factors did not vary between men with or without TML. However, men with TML did consume more crisp than men without. Development of TML was not associated to classic life style factors such as alcohol consumption, smoking habits, or mothers smoking during pregnancy. Also, age and height could not be linked to presence of TML. We did find, however, that men with TML experienced less physical activity and consumed more crisp than men without TML. Since ingestion of crisps has potential carcinogenic effect (acrylamide), this finding needs confirmation in a separate study.

Non-participation in breast cancer screening for women with chronic diseases and multimorbidity: a population-based cohort study.

BACKGROUND: Chronic diseases and multimorbidity are common in western countries and associated with increased breast cancer mortality. This study aims to investigate non-participation in breast cancer screening among women with chronic diseases and multimorbidity and the role of time in this association. METHOD: This population-based cohort study used regional and national registries. Women who were invited to the first breast cancer screening round in the Central Denmark Region in 2008-09 were included (n = 149,234). Selected chronic diseases and multimorbidity were assessed up to 10 years before the screening date. Prevalence ratios (PR) were used as an association measure. RESULTS: The results indicated that women with at least one chronic condition were significantly more likely not to participate in breast cancer screening. In adjusted analysis, a significantly higher likelihood of non-participation was found for women with cancer (PR = 1.50, 95% CI: 1.40-1.60), mental illness (PR = 1.51, 95% CI: 1.42-1.60), chronic obstructive pulmonary disease (PR = 1.51, 95% CI: 1.42-1.62), neurological disorders (PR = 1.24, 95% CI: 1.12-1.37) and kidney disease (PR = 1.70, 95% CI 1.49-1.94), whereas women with chronic bowel disease (PR = 0.75, 95% CI 0.65-0.88) were more likely to participate than women without these disease. Multimorbidity was associated with increased non-participation likelihood. E.g. having 3 or more diseases was associated with 58% increased non-participation likelihood (95% CI: 27-96%). Higher non-participation was also observed for women with severe multimorbidity (PR = 1.53, 95% CI: 1.23-1.90) and mental-physical multimorbidity (PR = 1.54, 95% CI: 1.36-1.75). CONCLUSION: In conclusion, we found a strong association between non-participation in breast cancer screening for some chronic diseases and for multimorbidity. The highest propensity not to participate was observed for women with hospital contacts related to the chronic disease in the period closest to the screening date.

Are Cancer Patients' Socioeconomic and Cultural Factors Associated with Contact to General Practitioners in the Last Phase of Life?

Introduction. General practitioners (GPs) play an important role in end of life care, which should be offered regardless of socioeconomic position and cultural factors. The aim was to analyse associations between GP contacts at the end of life and socioeconomic and cultural characteristics of Danish cancer patients. Method. Population-based study identifying 599 adults who died of cancer from March to November 2006, in Aarhus County, Denmark. Associations between health register-based data on "total GP face-to-face contacts" and "GP home visits" during the last 90 days of life and patients' socioeconomic and cultural characteristics were calculated. Results. Having low income (RR: 1.18 (95% CI: 1.03; 1.35)) and being immigrants or descendants of immigrants (RR: 1.17 (95% CI: 1.02; 1.35)) were associated with GP face-to-face contacts. However, patients living in large municipalities had lower likelihood of having both GP face-to-face contacts in general (RR: 0.85 (95% CI: 0.77;0.95)) and GP home visits (RR: 0.89 (95% CI: 0.80; 0.99)). Conclusion. This study indicates higher proportion of GP contacts to economically deprived patients and immigrants/descendants of immigrants. These subgroups were, however, small and results should be looked upon with caution. Furthermore, palliative needs were not included and together with urban/rural the underlying causes need further investigation.

A differentiated approach to referrals from general practice to support early cancer diagnosis - the Danish three-legged strategy.

When aiming to provide more expedited cancer diagnosis and treatment of cancer at an earlier stage, it is important to take into account the symptom epidemiology throughout the pathway, from first bodily sensation until the start of cancer treatment. This has implications for how primary-care providers interpret the presentation and decisions around patient management and investigation. Symptom epidemiology has consequences for how the health-care system might best be organised. This paper argues for and describes the organisation of the Danish three-legged strategy in diagnosing cancer, which includes urgent referral pathways for symptoms suspicious of a specific cancer, urgent referral to diagnostic centres when we need quick and profound evaluation of patients with nonspecific, serious symptoms and finally easy and fast access to 'No-Yes-Clinics' for cancer investigations for those patients with common symptoms in whom the diagnosis of cancer should not be missed. The organisation of the health-care system must reflect the reality of symptoms presented in primary care. The organisational change is evaluated and monitored with a comprehensive research agenda, data infrastructure and education.

Understanding missed opportunities for more timely diagnosis of cancer in symptomatic patients after presentation.

The diagnosis of cancer is a complex, multi-step process. In this paper, we highlight factors involved in missed opportunities to diagnose cancer more promptly in symptomatic patients and discuss responsible mechanisms and potential strategies to shorten intervals from presentation to diagnosis. Missed opportunities are instances in which post-hoc judgement indicates that alternative decisions or actions could have led to more timely diagnosis. They can occur in any of the three phases of the diagnostic process (initial diagnostic assessment; diagnostic test performance and interpretation; and diagnostic follow-up and coordination) and can involve patient, doctor/care team, and health-care system factors, often in combination. In this perspective article, we consider epidemiological 'signals' suggestive of missed opportunities and draw on evidence from retrospective case reviews of cancer patient cohorts to summarise factors that contribute to missed opportunities. Multi-disciplinary research targeting such factors is important to shorten diagnostic intervals post presentation. Insights from the fields of organisational and cognitive psychology, human factors science and informatics can be extremely valuable in this emerging research agenda. We provide a conceptual foundation for the development of future interventions to minimise the occurrence of missed opportunities in cancer diagnosis, enriching current approaches that chiefly focus on clinical decision support or on widening access to investigations.

Distance to screening site and non-participation in screening for breast cancer: a population-based study.

BACKGROUND: In population-based breast cancer screening programmes, the geographical distance to the screening site may influence a woman's propensity to participate. The aim of this study was to analyse the effect driving distance to the screening unit had on women's participation in a breast cancer screening programme. METHODS: All women invited to the first round of breast cancer screening in the Central Denmark Region were eligible for inclusion (n = 149,234). Information on participation was collected from a regional administrative database. The shortest road distance between each woman's residence and her affiliated screening site was assessed using Network Analyst, ArcGIS. RESULTS: The unadjusted association between distance and non-participation formed a J-shape curve. Adjustment for socio-demographic characteristics caused the J-shape to disappear, and the probability of non-attendance rose with longer distance to the screening site but flattened after ~45 km. Women without access to a vehicle had a higher risk of non-participation than women with access to a vehicle. CONCLUSIONS: A long road distance to the screening site was associated with an increased risk of non-participation. Women without access to a vehicle were at higher risk of non-participation than women who had access to a vehicle.

Childhood cancer and factors related to prolonged diagnostic intervals: a Danish population-based study.

BACKGROUND: Early diagnosis of childhood cancer provides hope for better prognoses. Shorter diagnostic intervals (DI) in primary care require better knowledge of the association between presenting symptoms, interpretation of symptoms and the wording of the referral letter. METHODS: A Danish nationwide population-based study. Data on 550 children aged <15 years with an incident cancer diagnosis (January 2007-December 2010) were collected through questionnaires to parents (response rate=69%) and general practitioners (GPs) (response rate=87%). The DI from the first presentation in general practice until diagnosis was categorised as short or long based on quartiles. Associations between variables and long DIs were assessed using logistic regression. RESULTS: The GPs interpreted symptoms as 'vague' in 25.4%, 'serious' in 50.0% and 'alarm' in 19.0% of cases. Symptom interpretation varied by cancer type (P<0.001) and was associated with the DI (P<0.001). Vomiting was associated with a shorter DI for central nervous system (CNS) tumours, and pain with a longer DI for leukaemia. Referral letter wording was associated with DI (P<0.001); the shortest DIs were observed when cancer suspicion was raised in the letter. CONCLUSION: The GPs play an important role in recognising early signs of childhood cancer as their symptom interpretation and referral wording have a profound impact on the diagnostic process.

Differences in cancer awareness and beliefs between Australia, Canada, Denmark, Norway, Sweden and the UK (the International Cancer Benchmarking Partnership): do they contribute to differences in cancer survival?

BACKGROUND: There are wide international differences in 1-year cancer survival. The UK and Denmark perform poorly compared with other high-income countries with similar health care systems: Australia, Canada and Sweden have good cancer survival rates, Norway intermediate survival rates. The objective of this study was to examine the pattern of differences in cancer awareness and beliefs across these countries to identify where these might contribute to the pattern of survival. METHODS: We carried out a population-based telephone interview survey of 19079 men and women aged ≥ 50 years in Australia, Canada, Denmark, Norway, Sweden and the UK using the Awareness and Beliefs about Cancer measure. RESULTS: Awareness that the risk of cancer increased with age was lower in the UK (14%), Canada (13%) and Australia (16%) but was higher in Denmark (25%), Norway (29%) and Sweden (38%). Symptom awareness was no lower in the UK and Denmark than other countries. Perceived barriers to symptomatic presentation were highest in the UK, in particular being worried about wasting the doctor's time (UK 34%; Canada 21%; Australia 14%; Denmark 12%; Norway 11%; Sweden 9%). CONCLUSION: The UK had low awareness of age-related risk and the highest perceived barriers to symptomatic presentation, but symptom awareness in the UK did not differ from other countries. Denmark had higher awareness of age-related risk and few perceived barriers to symptomatic presentation. This suggests that other factors must be involved in explaining Denmark's poor survival rates. In the UK, interventions that address barriers to prompt presentation in primary care should be developed and evaluated.

The Aarhus statement: improving design and reporting of studies on early cancer diagnosis.

Early diagnosis is a key factor in improving the outcomes of cancer patients. A greater understanding of the pre-diagnostic patient pathways is vital yet, at present, research in this field lacks consistent definitions and methods. As a consequence much early diagnosis research is difficult to interpret. A consensus group was formed with the aim of producing guidance and a checklist for early cancer-diagnosis researchers. A consensus conference approach combined with nominal group techniques was used. The work was supported by a systematic review of early diagnosis literature, focussing on existing instruments used to measure time points and intervals in early cancer-diagnosis research. A series of recommendations for definitions and methodological approaches is presented. This is complemented by a checklist that early diagnosis researchers can use when designing and conducting studies in this field. The Aarhus checklist is a resource for early cancer-diagnosis research that should promote greater precision and transparency in both definitions and methods. Further work will examine whether the checklist can be readily adopted by researchers, and feedback on the guidance will be used in future updates.

Social support, gender and patient delay.

BACKGROUND: The purpose of this study was to examine the relationship between perceived social support and patient delay (PD) among female and male cancer patients. METHODS: A population-based study with register-sampled cancer patients was designed. Patient delay was defined as the time interval between the patient's experience of the first symptom and the first contact with a health-care professional. Both dates were provided by the patients (n=910). The patients completed a purpose-designed questionnaire, which assessed the patient's perceptions of how the partner reacted ('Partner Avoidance' and 'Partner Support') and how others in the social network responded ('Other Avoidance' and 'Other Support') to the patient's worries about the symptoms. The associations between the social support subscales and PD were analysed separately for men and women. RESULTS: In female patients, Partner Support and Other Support were associated with shorter PD, whereas Other Avoidance was associated with longer PD. In the multivariate analysis, Other Avoidance remained associated with longer PD. Moreover, disclosure of symptoms to someone reduced the likelihood of a long PD in female patients. In male patients, none of the social support scales significantly increased or decreased the risk of a long PD in the univariate analysis, but Partner Support significantly decreased risk of a long PD in the multivariate analysis. CONCLUSIONS: The results of this study suggest that social support and avoidance from network members influence length of PD differently in male and female cancer patients. This gender difference may explain previous mixed findings obtained in this field.

Time to diagnosis and mortality in colorectal cancer: a cohort study in primary care.

BACKGROUND: The relationship between the diagnostic interval and mortality from colorectal cancer (CRC) is unclear. This association was examined by taking account of important confounding factors at the time of first presentation of symptoms in primary care. METHODS: A total of 268 patients with CRC were included in a prospective, population-based study in a Danish county. The diagnostic interval was defined as the time from first presentation of symptoms until diagnosis. We analysed patients separately according to the general practitioner's interpretation of symptoms. Logistic regression was used to estimate 3-year mortality odds ratios as a function of the diagnostic interval using restricted cubic splines and adjusting for tumour site, comorbidity, age, and sex. RESULTS: In patients presenting with symptoms suggestive of cancer or any other serious illness, the risk of dying within 3 years decreased with diagnostic intervals up to 5 weeks and then increased (P=0.002). In patients presenting with vague symptoms, the association was reverse, although not statistically significant. CONCLUSION: Detecting cancer in primary care is two sided: aimed at expediting ill patients while preventing healthy people from going to hospital. This likely explains the counterintuitive findings; but it does not explain the increasing mortality with longer diagnostic intervals. Thus, this study provides evidence for the hypothesis that the length of the diagnostic interval affects mortality in CRC patients.

Improved quality of Type 2 diabetes care following electronic feedback of treatment status to general practitioners: a cluster randomized controlled trial.

AIMS: To evaluate the effect of an electronic feedback system to general practitioners on quality of Type 2 diabetes care. METHODS: A cluster randomized, controlled trial with 15 months follow-up. Eighty-six general practices (158 general practitioners) in a Danish county caring for 2458 people 40-70 years old with Type 2 diabetes were randomized to receive or not to receive electronic feedback on quality of care. People with Type 2 diabetes were identified using a validated algorithm. Primary end-points were processes of care according to guidelines on prescriptions redeemed for Type 2 diabetes treatments, measuring of glycated haemoglobin and cholesterol and visits to ophthalmologists. Secondary end-points were changes in level of glycated haemoglobin and serum cholesterol. Data were analysed using generalized linear models accounting for clustering at practice level. RESULTS: During follow-up, people with Type 2 diabetes in the intervention group more often redeemed recommended prescriptions than people in the control group, respectively, as follows: oral antidiabetic treatment (32.8 vs. 12.0%, P =0.002), insulin treatment (33.8 vs. 12.4%, P < 0.001), lipid-lowering medication (38.3 vs. 18.6%, 0.004) and blood pressure medication (27.6 vs. 16.3%, P = 0.026). There were no differences in mean glycated haemoglobin and serum cholesterol between the two groups. CONCLUSIONS: Electronic feedback to general practitioners on the quality of Type 2 diabetes care resulted in significantly improved quality regarding processes of care according to guidelines. It was not possible to demonstrate any effect on secondary end-point measures within the follow-up period. Electronic feedback on quality of diabetes care can be effective in improving adherence to treatment according to evidence-based guidelines.

Delay in diagnosis: the experience in Denmark.

BACKGROUND: Denmark has poorer 5-year survival rates than many other Western European countries, and cancer patients tend to have more advanced stages at diagnosis than those in other Scandinavian countries. Part of this may be due to delay in diagnosis. The aim of this paper is to give an overview of the initiatives currently underway to reduce delays. METHODS: Description of Danish actions to reduce delay. RESULTS: Results of surveys of patient-, doctor- and system-related delays are presented and so are the political initiatives to ensure that cancer is seen as an acute disease. CONCLUSION: In future, fast-track diagnosis and treatment will be provided for suspected cancers and access to general diagnostic investigations will be improved. A large national experiment with cancer seen as an acute disease is currently being implemented, and as yet the results are unknown.

Intramuscular pressure and tissue oxygenation during low-force static contraction do not underlie muscle fatigue.

AIM: To test the hypothesis that time-wise increase in intramuscular pressure (IMP) and subsequent decrease in muscle tissue oxygenation (TO(2)) results in muscle fatigue development during a non-exhaustive, low-force contraction evidenced by changes in electromyogram (EMG) and particular mechanomyogram (MMG). METHODS: Seven subjects performed static elbow flexion at 10% maximal voluntary contraction (MVC) for 10 min (10% MVC(10 min)). Surface EMG, MMG, IMP and TO(2) measured by near-infrared spectroscopy was recorded from m. biceps brachii during 10% MVC(10 min) and during 5% MVC test contractions of 1 min duration performed before 10% MVC(10 min), 10 and 30 min post-exercise. EMG and MMG were analysed for root mean square (rms) and mean power frequency (mpf). RESULTS: During 10% MVC(10 min) MMGrms increased from initial level of 0.04 +/- 0.01 to 0.11 +/- 0.07 m s(-2) in the last minute and MMGmpf and EMGmpf decreased from 34.9 +/- 8.2 to 21.3 +/- 3.8 Hz and from 71.7 +/- 10.9 to 61.7 +/- 10.0 Hz respectively. Similar changes were present in 5% MVC test contractions 30 min post-exercise. Initially, TO(2) decreased by 6.9 +/- 6.5% of resting level but returned to rest within 1 min. IMP remained constant during the contraction after an initial fourfold increase from resting level of 12.2 +/- 10.4 mmHg. CONCLUSIONS: IMP was anticipated to increase with time of contraction due to e.g. increased muscle water content; but this was not confirmed. Consequently, muscle blood flow was unlikely to be impeded with contraction time, which may account for the maintenance of TO(2). Thus, decreased TO(2) did not underlie either acute or long-term muscle fatigue development evidenced by changes in EMG and particular MMG variables.

Frequent attenders in general practice care: a literature review with special reference to methodological considerations.

OBJECTIVE: To describe the basis on which our knowledge of frequent attendance in general practice rests and to propose recommendations for further research on frequent attenders (FAs). DESIGN: The literature review (finished February 2004) encompassed peer-reviewed articles in English describing contacts with general practice in terms of frequency. Searches were performed in the Medline, CINAHL, EMBASE, PsycINFO, Social Sciences Expanded Index and ISI Citation databases with additional searches in reference lists and the 'related articles' function in the ISI Citation database and Medline. SETTING: General practice. SUBJECTS: Sixty-one articles (54 studies). MEASURES: The articles were assessed according to the following design variables: setting; definition of FAs; sampling; sample size; control groups; study aim; study design; data sources; effect measure; and main results. RESULTS: There was no generally accepted definition of frequent attendance. Research designs differed substantially. Eight articles gave sufficient information on all design variables. The top 10% of attenders accounted for 30-50% of all contacts, and up to 40% of FAs were still FAs the following year. More than 50% of FAs had a physical disease, more than 50% of FAs suffered from psychological distress, social factors (low social support, unemployment, divorce) were associated with frequent attendance in more than 50% of FAs, multiproblems (physical, psychological and social) were found in one-third of FAs, and frequent attendance was associated with increasing age and female gender. CONCLUSION: The diversity of designs, definitions and methods in the current literature on FAs in general practice hampers comparison of their precision, validity and generalizability, and calls for cautious interpretation and adoption of a common, generally acceptable definition in future studies.

Muscle performance following fatigue induced by isotonic and quasi-isometric contractions of rat extensor digitorum longus and soleus muscles in vitro.

AIM: To study the effect of contraction mode on fatigue development. METHODS: Muscle fatigue was induced by isotonic and quasi-isometric contractions in rat soleus (SOL) and extensor digitorum longus (EDL) muscles, using identical stimulation protocol (60 Hz, 400 ms s-1) for 100 s in SOL and 60 s in EDL. Fatigue was quantified as the decline in peak values of shortening, shortening velocity, relaxation and work during the isotonic contractions, and, correspondingly, of force, rate of force development, relaxation and work during the quasi-isometric contractions. Maximal test contractions (60 Hz, 1.5 s) performed before and after fatigue were analysed for decline in force development (Fmax), rate of force development (dF/dtmax) and relaxation (-dF/dtmax). RESULTS: Fmax declined to significantly lower values after isotonic than after quasi-isometric fatiguing contractions (fatigued in percentage of unfatigued): 58.5 +/- 6.4% vs. 64.4 +/- 7.0% in SOL, and 30.4 +/- 4.1% vs. 33.3 +/- 3.6% in EDL, respectively. The same pattern was seen for dF/dtmax which decreased to: 46.3 +/- 9.9% vs. 52.3 +/- 8.5% in SOL, and 19.1 +/- 4.3% vs. 22.3 +/- 3.2% in EDL after isotonic and quasi-isometric contractions, respectively. Similarly, when comparing fatigue development during the two contraction modes, the respective fatigue variables decreased more rapidly and to lower levels during isotonic vs. quasi-isometric contractions. During maximal test contractions, the dynamic fatigue variables (+/-dF/dtmax) declined to significantly lower levels than Fmax. CONCLUSIONS: Fatigue development was significantly larger during isotonic vs. quasi-isometric contractions. The use of force as the only experimental fatigue variable may underestimate the functional impairment of fatigued muscle, neglecting the fatigue effect on time and length dimensions.