| 1. |
- Jonsson, Sarah, 1982-
(author)
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Pelvic inflammatory disease and epithelial ovarian tumors
- 2023
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Doctoral thesis (other academic/artistic)abstract
- Background: Epithelial ovarian cancer and borderline ovarian tumors consist of several histotypes in which high-grade serous carcinoma is the most common. The majority of epithelial ovarian tumors are considered to originate in the fimbriated end of the fallopian tubes. What initiates these tumors is far from completely understood. Pelvic inflammatory disease has been proposed as a modifiable risk factor for epithelial ovarian tumors. A major cause of pelvic inflammatory disease is Chlamydia trachomatis which has been shown to have cancer-causing potential. The overall purpose of this thesis was to study associations of pelvic inflammatory disease and C. trachomatis with risk of epithelial ovarian tumors.Methods: In a cross-sectional study (Paper I) we collected ovarian tissue and corresponding blood samples from 69 women undergoing surgery due to suspected ovarian pathology. C. trachomatis specific protein (immunohistochemistry) and C. trachomatis DNA (qPCR) in ovarian tissue were analyzed (Paper I). In a nested case-control study (Paper II) prospective blood samples from 92 women diagnosed with high-grade serous ovarian cancer were matched to four controls each for age and date of plasma sampling. C. trachomatis specific plasma antibodies were analyzed by commercial Enzyme-Linked ImmunoSorbent Assay (ELISA) and Micro-ImmunoFluorescence (MIF) (Paper I and Paper II). We performed a nationwide register-based case-control study where we included 15 072 women diagnosed with epithelial ovarian cancer (Paper III), 4782 women diagnosed with borderline ovarian tumors (Paper IV), and ten controls each matched for age and residential district. Using national Swedish registers, we retrieved data on historyof pelvic inflammatory disease and the potential confounding factors parity, educational level, previous gynecological surgery, and hormonal therapy.Results: We found C. trachomatis DNA in ovarian tissue of eight women with ovarian carcinoma, but not in ovarian tissue from women with borderline ovarian tumors or benign disease (Paper I). The prevalence of the C. trachomatis specific protein did not differ in benign and malignant tissue (Paper I). Prevalence of C. trachomatis specific plasma antibodies was similar in cases and controls at diagnosis (Paper I) and prospectively (Paper II). A history of clinically verified pelvic inflammatory disease was associated with an increased risk of epithelial ovarian cancer overall (Paper III) and borderline ovarian tumors overall (Paper IV). Histotype-specific analyses showed an increased risk of serous carcinoma (Paper III), high-grade serous carcinoma (Paper III), clear cell carcinoma (Paper III), and serous borderline ovarian tumors (Paper IV) but not significantly with other histotypes. A dose-response relationship was seen between an increased number of pelvic inflammatory disease episodes and epithelial ovarian cancer (Paper III), as well as borderline ovarian tumors (Paper IV).Conclusions: This thesis contributes to an improved understanding of the association between pelvic inflammatory disease and epithelial ovarian tumors. The results regarding C. trachomatis are inconclusive and suggests that the association of pelvic inflammatory disease with epithelial ovarian tumors acts through mechanisms other than Chlamydia alone.
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| 2. |
- Björ, Ove, 1967-
(author)
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Strategies for assessing health risks from two occupational cohorts within the domain of northern Sweden
- 2013
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Doctoral thesis (other academic/artistic)abstract
- Background: Studies based on a cohort design requires access to both subject-specific and period-specific information. In order to conduct an occupational cohort study, access to exposure information and the possibility and permission to link information on outcomes from other registers are generally necessary. The analysis phase is also aggravated by its added complexity because of the longitudinal dimension of the cohort’s data.This thesis aims at increasing the knowledge on hazards from work on fatalities and cancer within the domain of cohort studies on miners and metal refiners and to study the complexity of the analysis by discussing and suggesting analytical strategies.Methods: The study population for this thesis consisted of a cohort of 2264 blue-collar aluminium smelter workers (paper I) and a cohort of 13000 blue-collar iron-ore miners (papers II-IV), both followed for over 50 years. The outcomes were collected from the Swedish Cause of Death Register and the Swedish Cancer Register. The primary methods of analysis were either Standardized Morbidity Ratios (SMR) or internal comparisons based on Cox or Poisson regression modeling. In paper IV, a g-estimation based on an accelerated failure-time model was performed to estimate the survival ratio.Results: The results from paper I suggested that working as a blue-collar worker metal refiner was associated with increased rates of incidental lung cancer. Elevated rates among short term workers were observed for several outcomes. Paper I also showed that the choice of reference population when calculating SMR could influence the conclusions of the results. In paper II, several outcomes were elevated among the miners compared to the reference population from northern Sweden. However, no outcome except lung cancer was associated with cumulative employment time. The most recurrent pattern of the results was the negative association between cumulative employment time underground and several outcomes. The results from paper III showed that cumulative employment time working outdoors was associated with increased rates of cerebrovascular disease mortality. However, employment with heavy physical workloads did not explain the previously observed decreasing rates in the selected groups of outcomes. The adjustment for the healthy worker survivor effect by g-estimation in paper IV suggested that exposure from respirable dust was associated with elevated mortality risks that could not be observed with standard analytical methods.Conclusion: Our studies found several rates from the cohorts that were elevated compared to external refererence populations but also that long term employments generally were associated with decreasing rates. Furthermore, incidental lung cancer rates was found elevated for the metal refiners. Among the miners, mortality rates of cerebrovascular diseases depended on if work was performed outdoor (higher rates) or underground (lower rates). Methodologically, this thesis has discussed different analytical strategies for handling confounding in occupational cohort studies. Paper IV showed that the healthy worker survivor effect could be adjusted for by performing g-estimation.
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| 3. |
- Bordás, Pál, 1955-
(author)
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Evaluation of the effectiveness of mammography screening in Northern Sweden.
- 2010
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Doctoral thesis (other academic/artistic)abstract
- Service screening with mammography was implemented in Northern Sweden between 1989 and 1998, covering 190,000 women aged 40-74 years constituting the target population in the area. The aim of this thesis was the evaluation of mammography screening in Northern Sweden with special focus on selected screening performance indicators and on the disease outcome. We analysed interval cancer (IC) incidence and episode sensitivity in the Norrbotten Mammography Screening Programme (NMSP) for the period 1989-2002. An overall IC rate at 1.1/1000 and IC rate ratio at 38% was found and epsiode sensitivity was estimated at 62-73%, in concert with reference values of the European guidelines. Radiological classification of the IC cases in three rounds of the NMSP showed that true, occult, missed and minimal signs IC, were present in 48%, 10%, 14% and 28% of the cases. We analysed early death from breast cancer (n=342) in Northern Sweden during the first five years of mammography service screening. Most fatal cases were advanced and incurable on diagnosis. In a few screen-detected cases with favourable prognostic factors the fatal outcome was unexpected. We estimated breast cancer survival by detection mode in 5120 women with breast cancer. We found a significantly favourable survival among IC cases compared to cases among uninvited. We studied breast cancer mortality in relation to mammography screening. Our findings indicated a long-term reduction of breast cancer mortality by 26-30% among women invited to screening and by 31-35% among women screened compared to not screened. We conclude from our evaluation of the mammography screening in Northern Sweden that women benefited from this public health intervention in form of improved survival and reduced mortality.
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| 4. |
- Holmström, Benny, 1974-
(author)
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Early diagnosis and treatment of prostate cancer : observational studies in the National Prostate Cancer Register of Sweden and the Västerbotten Intervention Project
- 2011
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Doctoral thesis (other academic/artistic)abstract
- Prostate-specific antigen (PSA) testing has caused a steep increase in the incidence of prostate cancer, especially the incidence of localised low risk disease. In order to decrease the overdiagnosis accompanied by PSA testing, analysis of inherited genetic variants have been suggested as potential tools for clinical assessment of disease risk. With the aim of minimizing overtreatment and postpone side-effects of curative treatment for low risk prostate cancer, active surveillance, a treatment strategy with initial surveillance and deferred radical prostatectomy at the time of progression has evolved. The aim of this thesis was to study the validity of PSA (paper I) and inherited genetic variants (paper II) for early diagnosis of prostate cancer, to assess the extent of PSA testing in Sweden (paper III), and to study the safety of deferred radical prostatectomy in localised low to intermediate risk prostate cancer (paper IV). The study designs were i) case-control studies nested within the Västerbotten intervention project (paper I and II), ii) observational study in the Cancer Register of Sweden (paper III), and iii) observational study in the NPCR Follow-up study (paper IV). PSA had a high validity in predicting a prostate cancer diagnosis with an area under the receiver operating characteristics (ROC) curve of 0.86 (95% CI, 0.84 to 0.88). A combined test, including PSA, the ratio of free to total PSA, and 33 single nucleotide polymorphisms (SNPs) in a genetic risk score, increased the area under curve to 0.87 (95% CI, 0.85 to 0.89). The estimated uptake of PSA testing among men aged 55 to 69 years increased from zero to 56% between 1997 and 2007 and there were large variations in the uptake of PSA testing between counties in Sweden. After a median follow-up time of eight years there was no significant difference in presence of any one or more adverse pathology features or prostate cancer specific mortality after primary compared to deferred radical prostatectomy in localised low to intermediate risk prostate cancer. Results from these studies indicate that PSA and the hitherto identified SNPs are not suitable biomarkers in single-test prostate cancer screening. It is possible to estimate the uptake of PSA testing on a population level. Initial surveillance and deferred radical prostatectomy represent a feasible treatment strategy in localised low to intermediate risk prostate cancer.
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| 5. |
- Numan Hellquist, Barbro, 1982-
(author)
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Breast cancer screening with mammography of women 40-49 years in Sweden
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Background The debate regarding the lower age limit for mammography service screening is old and lively; a product in part of the lower breast cancer risk in younger ages as well as the limited data available for studies of the younger age group. Recently the idea of inviting only high risk groups has gained momentum, however high risk might not be equivalent to greater benefit from screening. Therefore, there is a need for information on effectiveness of screening as it relates to young women and to specific risk groups. To this end, this thesis evaluates mammography screening for the age group – 40 to 49 year old women – in terms of breast cancer mortality reduction in total and in subgroups based on breast cancer risk factors. Overdiagnosis of mammography screening is also evaluated for women 40 to 49 years old. In addition, this thesis presents a statistical method to estimate this effectiveness and to test for differences in effectiveness between subgroups adjusted for non-compliance and contamination.Methods The studies of this thesis are based on data from the Screening of Young Women (SCRY) database. The SCRY database consists of detailed information on diagnosis, death, screening exposure and risk factors for breast cancer cases and population size by year (between 1986 and 2005) and municipality for women in Sweden between 40 and 49 years old. The material was divided into a study group consisting of the counties that invited women in the age group 40-49 years to mammography screening, and a contemporaneous control group consisting of the counties that did not. Effectiveness was estimated in terms of rate ratios for two different exposures (invitation to and participation in screening), and overdiagnosis for subsequent screening was estimated adjusting for lead time bias. Defining a reference period enabled adjustment for possible underlying differences in breast cancer mortality and incidence. A statistical model for adjusting for non-compliance and contamination in randomised controlled trials was further developed to allow for adjustment in cohort studies using a Poisson model with log-linear structure for exposure and background risk.Results During the study period (1986-2005), there were 619 and 1205 breast cancer deaths and 6047 and 7790 breast cancer cases in the study group and the control groups, respectively. For women between 40 and 49 years old, the breast cancer mortality reduction was estimated at 26% [95% CI, 17 to 34%] for invited to screening and 29% [95% CI, 20 to 38%] for attending screening. The RR estimates for the high-risk groups based on the risk factors parity, age at birth of first child, and socio-economic status were equal to or higher than that of the low risk groups. The new statistical method showed that the decrease in effectiveness with parity was not a statistically significant trend. The overdiagnosis from subsequent screening for 40 to 49 year old women was estimated at 1% [95 % CI, -6 to 8 %] (i.e., not statistically significant).Conclusion Subgroup specific effectiveness was also estimated. The relative effectiveness of screening for breast cancer with mammography for women age 40 to 49 years appears to be comparable to that for older women. These findings and the fact that there was no statistically significant overdiagnosis from subsequent screening speak for inviting women 40 to 49 years old to screening. High-risk screening for nulliparous women aged 40 to 49 years, for example, might be an alternative in countries where population-based screening for all women between 40 and 49 years old is not possible. However, the matter of risk factors and the effect of their combinations is complex and risk group screening presents ethical and practical difficulties. The new statistical model is a useful tool for analysing cohorts with exposed and non-exposed populations where non-compliance and contamination is a potential source of bias.
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| 6. |
- Bergström, Ulrica, 1970-
(author)
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Fragility fractures in fragile people : epidemiology of the age quake
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Osteoporosis-related fracture is already today a major public health problem and the number of hip fractures is expected to double to 2030. Sweden has one of the highest hip fracture incidences worldwide. This may be explained by several factors: e.g. age, genetic, climatologic, geographic and a relative vitamin D deficiency, secondary to the limited sunlight exposure especially during winter months. Intrinsic and extrinsic factors contribute to a fracture, although a prior low energy fracture is one of the strongest predictors for a subsequent one and this should be a target for secondary fracture prevention in an orthopaedic setting. Since 1993 all injured patients admitted to the emergency floor and all in-hospital fractures at Umeå University Hospital, Sweden, were registered according to the Injury Data Base, former EHLASS. There were 31,173 fracture events (one or more fractures at the same time), of which 13,931 were in patients’ ≥ 50 years old. The fracture database was co analyzed with the Northern Sweden Health and Disease Study cohort in a nested case-control study for investigations of associations between osteoporotic fracture and serum markers, lifestyle data, nutrition etc. We found that there were differences in fracture pattern depending on age and sex. Both injury mechanism and fracture site were strongly dependent of age. The most severe fragility fracture, hip fracture, had a decreasing incidence. However, the incidence curve was right-shifting leading to an increase, both in numbers and in incidence of hip fractures among the oldest female. To identify people at high risk for fractures, re-fracture patients are useful. No less than 21% of the fracture patients had suffered more than one fracture event, accounting for 38% of all fracture events. The total risk ratio for a subsequent fracture was 2.2 (2.1-2.3 95% CI). In males the highest risk for re fracture was in the age cohort 70-79 years (RR 2.7, 2.3-3.2 95% CI), in females > 90 years (RR 3.9, 3.2-4.8 95% CI). Another possible risk factor in this subarctic population is the lack of sunlight, leading to a vitamin D deficit. The overall adjusted risk of sustaining a hip fracture in this population was 2.7 (95%CI:1.3-5.4) in subjects with a serum 25 hydroxyvitamin D below 50 nmol/l. The association was, however, different according to age at baseline. Thus in subjects aged 60 years and above at baseline, the adjusted odds ratio of sustaining a hip fracture was 6.2 (1.2-32.5 95%CI) for the group of individuals with a serum 25OHD below 50 nmol/l, whereas no significant association was found in the youngest age group. In the next 30 years the ongoing demographic changes will accelerate. The World War II baby boomers will cause an age quake. We can already see signs heralding a new fracture pattern: an increasing cohort of mobile but fragile elderly, with considerable co-morbidity is now at risk for fragility fractures. In fracture patients, clinical information is sufficient to pinpoint patients with a high risk for re-fractures. It is therefore clinically important to use the information provided by the fracture event. We suggest that trauma units and primary care units should screen for risk factors and inform patients about the treatment options, and to organize fracture liaison services. This seems to be especially cost-efficient for our oldest and frailest patients. Secondary prophylaxis and follow-up treatment after cardiovascular disorders are now a matter of course worldwide, but the screening for risk factors, in order to prevent a second fracture, is often neglected. This is one of the most important issues of fracture care in the future in order to improve general health.
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| 7. |
- Ekbladh, Elin, 1974-
(author)
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Return to Work : Assessment of Subjective Psychosocial and Environmental Factors
- 2008
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Doctoral thesis (other academic/artistic)abstract
- Introduktion: Sjukfrånvaron i Sverige är hög och kunskap om vad som påverkar återgång i arbete efter sjukskrivning behöver utvecklas. I processen kring återgång i arbete är bedömning av arbetsförmåga en viktig del. Bristen på valida, reliabla och teoretiskt förankrade bedömningsinstrument inom området är dock ett bekymmer eftersom tillförlitliga bedömningar av arbetsförmåga är en förutsättning för utformning och genomförande av interventioner för att stödja återgång i arbete. Denna typ av interventioner kräver multidisciplinär kompetens där arbetsterapeuter utgör en viktig funktion. Vid bedömning av arbetsförmåga bör personens subjektiva uppfattning om sin situation beaktas, då den har betydelse för utfallet av återgång i arbete. Worker Role Interview (WRI) och Work Environment Impact Scale (WEIS) är två arbetsrelaterade intervjuinstrument, som har utvecklats i syfte att bedöma subjektiva psykosociala och miljömässiga faktorers påverkan på arbetsförmåga. Den teoretiska grunden till WRI och WEIS är Model of Human Occupation, som är en modell med fokus på aktivitetsutförande i relation till psykosociala faktorer. Inledande prövningar av WRI och WEIS reliabilitet och validitet har genomförts. Bedömningsinstrumenten har bearbetats och översatts till svenska och används främst av arbetsterapeuter, som arbetar med personer med arbetsrelaterad problematik.Syfte: Det övergripande syftet med avhandlingen är att undersöka användbarheten av bedömningsinstrumenten Worker Role Interview och Work Environment Impact Scale för identifiering av psykosociala och miljömässiga rehabiliteringsbehov av betydelse för återgång i arbete.Metod: Avhandlingen består av fem empiriska studier. I samtliga studier har erhållen information bearbetats kvantitativt. I studie IV har även kvalitativ bearbetning genomförts. Studie I, II och IV är tvärsnittsstudier och studie II och V är två års longitudinella studier. I studie I samlades information in via enkät. I studie II, III och V bestod den huvudsakliga informationen av skattningar utifrån WRI variabler och i studie IV var bedömningar utifrån WEIS i form av skattningar och nedskrivna kommentarer till skattningarna den huvudsakliga informationen.Resultat: I studie I undersöktes vilka teoretiska utgångspunkter och professionsspecifika modeller arbetsterapeuter i Sverige ansåg påverka den psykiatriska vården och den psykiatriska arbetsterapin. Det psykosociala perspektivet var den teoretiska utgångspunkt som hade störst påverkan både på psykiatrisk vård och på psykiatrisk arbetsterapi. Den arbetsterapeutiska modell som flest identifierade var Model of Human Occupation. Detta resultat indikerar att Model of Human Occupation verkar vara användbar inom arbetsterapi och motiverade vidare användning av modellen i denna avhandling. Det som dock också framkom i studie I var att arbetsterapeuter inom psykiatrisk vård använde professionsspecifika modeller i en relativt liten utsträckning. Ett sätt att öka tillämpningen av teori i praktik är att använda teoretiskt grundade bedömningsinstrument. I studie II, III, IV och V har endera av de Model of Human Occupation- baserade bedömningsinstrumenten WRI och WEIS använts och värderats.I studie II och V prövades WRI:s förmåga att predicera återgång i arbete efter långvarig sjukskrivning. Det område i WRI som uppvisade bäst prediktivitet var området ”Självuppfattning” vars variabler beaktar personens motivation för återgång i arbete i form av personens upplevelse av kompetens och effektivitet för att utföra arbetsuppgifter och hantera utmaningar i arbetet. De två WRI variabler som bäst kunde predicera vilka som skulle återgå respektive inte återgå i arbete vid uppföljning efter två år var: ”Tro på sin arbetsförmåga”, och ”Dagliga vanor och rutiner”. Resultaten tyder på att kunskap om hur tro på den egna förmågan stärks och kunskap om dagliga vanor och rutiners påverkan på utförande av arbete är central vid genomförande av interventioner i syfte att stödja personer att återgå till arbete efter sjukskrivning.I studie III prövades WRI:s konstrukturella validitet i en internationell studie. Samtliga variabler i WRI, förutom de som tillhör miljöområdet, uppvisade en god konstrukturell validitet dvs mätte psykosociala faktorers påverkan på arbetsförmågan. WRI:s skattningsskala verkar stabil och valid mellan olika länder och för personer med olika diagnoser. I analysen framkom att WRI kunde särskilja mellan personers psykosociala arbetsförmåga på tre olika nivåer.I studie IV undersöktes hur personer med erfarenhet av långtidssjukskrivning uppfattar att faktorer i arbetsmiljön stödjer respektive hindrar personens utförande av arbete och välbefinnande genom bedömningar utifrån WEIS. De faktorer som uppfattades som meststödjande var olika former av sociala interaktioner på arbetet samt uppfattningen om arbetets värde och mening. De faktorer som uppfattades som mest hindrande var olika krav i relation till arbetsgenomförandet samt den belöning som erhålls för arbetet.Konklusion: Sammanfattningsvis så kan WRI användas för bedömning av psykosociala faktorers påverkan på arbetsförmågan. I WRI ingår variabler som kan predicera återgång till arbete upp till två år efter genomförd bedömning. WEIS verkar användbart för att identifiera arbetsmiljöfaktorer som stödjer respektive hindrar personers välbefinnande och utförande av arbete. Att komplettera olika datainsamlingsmetoder är en förutsättning för att uppnå en så god bedömning av arbetsförmåga som möjligt. Den information som WRI- och WEISintervjuer genererar är värdefull, då den kan utgöra en viktig grund för planering av individspecifika rehabiliteringsinsatser. Bedömningsinstrumenten WRI och WEIS med sin teoretiska förankring i Model of Human Occupation kan anses vara användbara för att identifiera psykosociala och miljömässiga rehabiliteringsbehov i syfte att stödja personer i processen åter till arbete efter sjukskrivning.
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| 8. |
- Magnusson Sporre, Cecilia, 1968-
(author)
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Måltidsgörarens utmaningar : komplexiteten i det medvetna måltidsgörandet
- 2015
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Doctoral thesis (other academic/artistic)abstract
- I denna avhandling synliggörs måltidsgörarna, en omfångsrik grupp med skilda kompetenser och yrkesprofessioner. Det gemensamma är att alla är delaktiga i måltidsgörandet genom planering, tillagning och service av måltider serverade i olika verksamheter. Avhandlingen är kvalitativ, ett empiriskt-holistiskt perspektiv, med relevans både inom och utom akademin, en så kallad frågedriven tvärvetenskap.Avhandlingens övergripande syfte är att synliggöra måltidsgörandet och den komplexitet som utmärker måltidsgörarens profession och uppgift. Detta besvaras genom fyra artiklar, uppdelat i delstudie 1: FAMM och delstudie 2: Den medvetna måltiden. Metoder som använts i studien är, forskningscirklar, dokumentstudier, intervjuer och kvalitativ innehållsanalys. Avhandlingen belyser tre perspektiv: Ett samhälleligt perspektiv, där människors mat- och måltidsvanor relateras till samhällsutvecklingen. måltidsperspektivet som är kärnan i hela avhandlingen samt kunskapsperspektivetsom har betydelse för den gastronomiska utbildningen.Avhandlingens bidrag är att belysa: hur FAMM har vandrat från den akademiska gastronomikontexten till statliga myndigheter och vidare till måltidsgörarnas olika yrkesprofessioner i de offentliga storköken i kommuner och landsting; måltidsgörarnas komplexa och meningsskapande professioner och utmaningar i arbetet med måltidsgörandet; Den nya medvetna måltidens komplexitet med ett måltidsgörande där alla stadier genomsyras av etisk reflektion (att veta hur), från jord till bord; behovet av universitetsutbildning med gastronomiskt perspektiv samt kompetensutveckling för offentlig sektors måltidsgörare.Den gastronomiska diskursen som framträder i den offentliga måltidssektorn pekar åt samma håll som den så kallade gastronomiska revolutionen inom restaurangnäringen. Resultaten öppnar för intressanta fortsatta studier av det politiska matklimatets betydelse för måltidsgörarna och måltidsgörandet.
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| 9. |
- Sundell, Claes-Göran, 1950-
(author)
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Low back pain in adolescent athletes
- 2019
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Doctoral thesis (other academic/artistic)abstract
- Background: Globally Low back pain (LBP) is one of five leading causes of years lived with disability (YLD), and LBP is a common complaint among adults as well as adolescents and adolescence athletes. During adolescents, the LBP often is considered as non- specific without structural findings and thus not needed to be further diagnosed or treated specifically. However, LBP that begins in adolescence often continue through adulthood, and since adolescent athletes with high physical activity seems to have more LBP than less physically active adolescents, high physical loading during adolescence, might be a risk factor for LBP later in life.Studies: Epidemiology: The Standardized Nordic Questionnaire adjusted for adolescence was used to investigate the prevalence of LBP during adolescence (16-19 years old individuals).Retrospective study: A ten-year follow-up on symptomatic low back spondylolysis patients identified on MRI or CT. Sixteen out of nineteen identified patients agreed to answer a questionnaire and to have their case-history reviewed.Case-control study: Twenty-five patients (13-19-year-old boys and girls) with LBP and 13 pain free individuals (controls, 14-19-year-old boys and girls) were investigated with physical examination and MRI. If the patients had findings on MRI a CT investigation was performed.Clinical study: Twelve of 14 patients (a subgroup from the case-control study) with Spondylolysis on MRI and CT were evaluated with a modified Hollenberg classification (six levels). These patients were re-evaluated with MRI and CT after 3 months of treatment with complete rest from sports activity.Differential diagnosis: Five adolescent patients with on-going LBP/thigh pain previously treated in other clinics, were reevaluated for a “second opinion”.Results: Epidemiology study: The prevalence of LBP among adolescents was 46% (N= 2522) with an annual incidence of 42 %. Girls reported more LBP than boys (52 % versus 40 %). Individuals who were active in sports > 6 h/w had significantly more LBP compared with less physically active individuals. Retrospective study: Thirteen of the 16 individuals had a second MRI/CT investigation and thus 52 out of the initial 64 pars interarticularis where investigated a second time (mean 3 months after the first investigation). These patients had had different treatments, most commonly rest for 3 months. In total, 7 out of 16 individuals healed (44%).Case control study: In 22/25 patients (88%) there were clinical findings and MRI findings such as spondylolysis, disc herniated discs, disc degeneration and injuries to the vertebral body. In 13/25 patients (52%) spondylolysis of different stages were found. No clinical test alone, or in combination, could reliably diagnose spondylolysis, and could thus not be used as a selection test for patients who need further diagnostics with MRI and CT.Clinical study: Using a combination of MRI and CT examination the early signs of skeletal injury (oedema, incomplete fracture) to the pars interarticularis were detected. Patients diagnosed with these early stages healed significantly better than if diagnosed in later stages (complete fracture and pseudoarthrosis).Differential diagnosis: The second opinion with careful physical examination and MRI examination diagnosed stress reactions in the pelvic ischial tuberosity in the patient seeking help for pain in the lower back/thigh. After guided rehabilitation, all these patients returned to previous sport activities.Conclusions: LBP is common during adolescence, more common in girls and in highly active individuals. LBP must be taken seriously, especially in adolescent athletes who not seldom have fractures in pars interarticularis (Spondylolysis). If diagnosed early, there seems to be good potentials to heal the fracture with 3 months ́ of rest from loading (sport activity). Differential diagnoses such as stress reactions in the pelvic ischial tuberosity should be taken into consideration.
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| 10. |
- Wirén, Sara, 1981-
(author)
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Prospective studies of hormonal and life-style related factors and risk of cancer
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Background: Androgens are important in prostate cancer development but how circulating levels of androgens affect risk of prostate cancer of different aggressiveness is not clear. Being childless has been associated with a lower risk of prostate cancer, but it is not clear if this association is causal or a result of residual confounding. Fathering of dizygotic twins, a marker of high fertility, has not been studied in relation to risk of prostate cancer.Another marker of life-long hormonal exposure is height, which has been associated with increased risk of cancer and cancer death. However, the association to separate cancer sites has not been consistent.The aims of this thesis were to study hormonal factors (paper I), and proxies of hormonal factors (paper II and III), and risk of prostate cancer; as well as height and risk of cancer and cancer death by separate sites (paper IV).Methods: Study designs were i) case-control studies, nested within the Västerbotten Intervention Project (paper I), and in Prostate Cancer database Sweden 2.0 (PCBaSe 2.0) (paper II and III), and ii) cohort study, in the Metabolic Syndrome and Cancer project (Me-Can) (paper IV).Results, prostate cancer: In paper I, increasing levels of serum androgens were not associated with risk of prostate cancer overall or in tumor risk categories. In paper II, childless men had a lower risk of prostate cancer, overall and in all risk categories, compared to fathers, an association which was in part explained by differences in marital status and educational level. In paper III, fathers of dizygotic twins did not have an increased risk of prostate cancer, either overall or in risk categories, when compared to fathers of singletons.Results, cancer overall: In paper IV, height was associated with an increased risk of cancer and cancer death overall in both women and men. The strongest association for cancer was to malignant melanoma in both women and men, and for cancer death to post-menopausal breast cancer in women and renal cell carcinoma in men.Conclusions: These studies indicate that hormonal factors, when studied as serum levels or when studied using proxies of fertility, do not have a major impact on the risk of prostate cancer. The association between height and an increased risk of cancer appears robust for total cancer and cancer death, as well as for several separate cancer sites.
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