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PubMed1993

Is the incidence of dementing illness changing? A 25-year time trend study in Rochester, Minnesota (1960-1984)

We performed a time trend study of incidence of dementing illness in Rochester, Minnesota. We ascertained age- and sex-specific incidence rates for the five quinquennia, 1960 through 1984. The incidence rates sharply increased with advancing age, reaching a high of 2,922/100,000 person years in the group 85 years and older. For dementia caused either solely or predominantly by Alzheimer's disease, this figure was 2,600/100,000 person years for the oldest age group. There were no significant differences in the incidence of dementing illness between men and women. In the oldest age groups in the last two quinquennia of study, there appears to be a trend toward increasing incidence rates. Over the years, the proportion of cases attributed to dementia due to unknown causes has decreased while the proportion of cases attributed to Alzheimer's disease has increased.

Adult↗

PubMed1999

Time trends of incidence for cutaneous melanoma among the Japanese population: an analysis of Osaka Cancer Registry data, 1964-95.

Cutaneous malignant melanoma occurs much less frequently among non-white populations than among white populations. Little is known of the descriptive epidemiology of melanoma among Japanese. We investigated time trends of incidence of invasive cutaneous malignant melanoma using data from the Osaka Cancer Registry (Japan) among 321 men and 313 women diagnosed between 1964-95. Average, annual, age-standardized incidence rates per 1,000,000 population were 2.45 (95% confidence interval (CI): 2.17-2.72) for men and 2.04 (95% CI: 1.81-2.28) for women. The age-standardized rate ratio among men from 1964-71 as a reference was almost constant during the study period, whereas that among women increased up to 1.8 fold (95% CI: 1.25-2.56) in 1980-87 and seems to have reached a plateau recently. Among men, the ratio for head and neck lesions decreased to 0.5 fold (95% CI: 0.26-0.99) in 1988-95. Among women, the ratio for lesions of the extremities steeply increased up to 4.7 fold (95% CI: 2.68-8.35) in 1980-87 from the reference period of 1964-71, whereas a slight increase for trunk lesions and no increase for head and neck lesions were noted during the same period. Possible explanations for the subsite-specific time trends are discussed.

Adolescent↗

PubMed1987

Time trends in characteristics at diagnosis and subsequent survival for Caucasian, Japanese and Hawaiian women with breast cancer in Hawaii.

This study examines whether the improvement in breast cancer survival in Hawaii suggested by an earlier analysis might be explained by concomitant temporal variations in prognostic factors. Characteristics at diagnosis and survival experience were compared for 1251 Caucasian, 1015 Japanese and 505 Hawaiian women diagnosed with invasive breast carcinoma during 1960-1979 and followed until the end of 1982. Time-trends were present for the patients' stage at diagnosis, age and socioeconomic status. A multivariate analysis using the Cox proportional hazards regression model revealed that adjustment for temporal variations in stage and age at diagnosis yielded a positive survival trend of a greater magnitude than that observed without adjustment, indicating that multivariate methods should be considered in time-trend analyses of cancer survival. Further analysis revealed that such improvement in breast cancer survival occurred for certain race-stage groups of patients only. Possible reasons for these trends in breast cancer prognostic factors and survival are discussed, along with potential biases. The data suggest that early detection might explain most of the survival improvement in Hawaii during the period of the study.

Adult↗

PubMed1991

Time trends in malignant melanoma of the upper limb in Connecticut.

Time trends in the incidence of malignant melanoma of the anatomic subsites of the upper limb in Connecticut from 1935 to 1984 were examined. Among males, the incidence of melanoma of the hand was stable, in sharp contrast to the 15-fold to 16-fold increase in the upper arm and forearm. Among females, the 3-fold increase in melanoma of the hand was substantially less than the 12-fold to 14-fold increase in the upper arm and forearm. However, melanoma of the dorsal surface of the hand in females increased sevenfold. These results are in partial agreement with the hypothesis that the hand would be relatively resistant to increased melanoma incidence because it has continually been a sun-exposed site over the decades. The results contradict the hypothesis that the rise in incidence would be greater in the upper arm (a usually unexposed site that has received increasing exposure due to changes in recreation and dress habits) than in the forearm (a site of intermediate exposure).

Arm↗

PubMed1999

Leukemias and lymphomas: time trends in the UK, 1984-93.

OBJECTIVE: To investigate recent time trends of some selected and common neoplasms of the blood and lymphatic tissues. METHODS: A specialist population-based register of hematological and related neoplasms was set up in parts of the UK in 1984. Secular changes over the first 10 years were investigated using log-linear Poisson modeling. The results are presented in tabular and graphical form. RESULTS: The analyses of 26,899 cases revealed a decline in incidence of acute myeloid leukaemia (AML), the myeloproliferative disorders (MPD) including chronic myeloid leukaemia (CML) and, in males only, Hodgkin's disease (HD). No secular trends for acute lymphoblastic leukaemia (ALL) were observed at any age. A marked increase in incidence in non-Hodgkin's disease (NHL) and the pre-leukemia group of myeloid dysplasias (MDS) was found. CONCLUSIONS: The rise in MDS and decline in AML and related conditions are most likely to reflect diagnostic changes. Changes in NHL may reflect, in part, a similar phenomena, but an underlying upward trend cannot be excluded. The decline in HD is in one gender only and the significance of this remains to be investigated.

Adolescent↗

PubMed2006

Nosocomial infection surveillance in a surgical intensive care unit in Spain, 1996-2000: a time-trend analysis.

OBJECTIVE: To establish the occurrence, distribution, and secular time trend of nosocomial infections (NIs) in a surgical intensive care unit (ICU). DESIGN AND SETTING: Follow-up study in a teaching hospital in Spain. METHODS: In May 1995 we established an nosocomial infection surveillance system in our surgical ICU. We collected information daily for all patients who were in the ICU for at least 48 hours (546 patients from 1996 through 2000). We used the Centers for Disease Control and Prevention definitions and criteria for infections. Monthly, we determined the site-specific incidence densities of NIs, the rates of medical device use, and the Poisson probability distribution, which determined whether the case count equalled the number of expected cases (the mean number of cases during the previous year, with extreme values excluded). We compared yearly and monthly infection rates by Poisson regression, using site-specific NIs as a dependent variable and year and month as dummy variables. We tested annual trends with an alternative Poisson regression model fitting a single linear trend. RESULTS: The average rate of catheter-associated urinary tract infections was 8.4 per 1000 catheter-days; that of ventilator-associated pneumonia, 21 per 1000 ventilator-days; and that of central line-associated bloodstream infections, 30 per 1000 central line-days. The rate of urinary tract infections did not change over the study period, but there was a trend toward decreases in the rates of central line-associated bloodstream infections and ventilator-associated pneumonia. CONCLUSION: An NI surveillance and control program contributed to a progressive decrease in NI rates.

Catheterization, Central Venous↗

PubMed1996

[Time trends of digestive system tumor mortality in Italy, 1970-89].

Time trends of mortality from digestive cancers in Italy during the period 1970-1989 were here studied either at the national level and for wide geographical areas (North, Center and South). Cancers of oral cavity and pharynx, of colon and rectum, of gallbladder and of the pancreas presented, during the considered period a generalized increasing trend. Stomach cancer mortality was decreasing in both sexes and in all areas, but a less marked rate of decrease appeared for younger cohorts, particularly for women. Trends almost stable, or contrasting across sexes and age classes, were observed for malignant tumours of the oesophagus and of the liver.

Adolescent↗

PubMed2007

Influenza vaccination among persons with chronic respiratory diseases: coverage, related factors and time-trend, 1993-2001.

BACKGROUND: Influenza vaccination has shown itself to be effective in reducing morbidity and mortality in patients with underlying chronic respiratory diseases. This study sought to: (1) estimate influenza vaccination coverage among asthma and chronic bronchitis sufferers; (2) ascertain which variables were associated with vaccination; and (3) analyse the time-trend in coverage between 1993 and 2001. METHODS: This was a descriptive study covering the 2611 subjects included in the 1993, 1995, 1997 and 2001 Spanish National Health Surveys who reported suffering from asthma or chronic bronchitis. Vaccination coverage was calculated for each year and the influence of socio-demographic and health-related variables analysed. Using logistic regression, we assessed which of the variables had an independent effect on vaccination, and analysed the time-trend. RESULTS: The proportions of vaccinated subjects in 1993, 1995-1997 and 2001 were 44.7%, 45.6% and 44.4%, respectively. Variables that increased the likelihood of having been vaccinated were: higher age, presence of another concomitant chronic disease, poor perception of health, non-smoker status, and being married. There was no significant variation in coverage over the study period. CONCLUSION: Influenza vaccination coverage among Spanish asthma and/or chronic bronchitis sufferers is below desirable levels and showed no improvement over the period 1993-2001. Implementation of strategies to improve coverage is necessary.

Adolescent↗

PubMed1993

Time trends of early gastric carcinoma. A clinicopathologic analysis of 2846 cases.

BACKGROUND: Despite recent improvements in the diagnostic accuracy and techniques for identifying early gastric carcinoma, gastric carcinoma remains a major cause of death in the world. METHODS: The clinicopathologic features of 2846 surgically resected early gastric carcinomas from 1962-1987 were reviewed, and the time trends of a variety of clinicopathologic factors were studied using both an univariate and a multivariate analysis. RESULTS: The differentiated type of carcinoma increased in frequency from 34-50%. The percentage of patients older than 60 years of age increased from 32-56%. The number of lesions measuring less than 3 cm increased from 28-56%. The frequency of shallow-type-IIc carcinomas measuring less than 3 cm, which had been previously difficult to detect and were mainly composed of differentiated carcinomas, increased from 46-69%. The relative proportion of the differentiated type of carcinoma was significantly higher in patients older than 60 years of age than in those younger than 60. The relative proportion of differentiated-type carcinomas measuring less than 3 cm, which had been easy to detect as opposed to undifferentiated-type carcinomas, significantly increased from 56-76%. CONCLUSIONS: The above time trends may indeed reflect genuine change. However, the recent increase in the rate of differentiated-type, small-sized carcinomas also suggests the possibility that such results may, in fact, be due mainly to improvements in both diagnostic accuracy and medical technology. Thus, a large number of undifferentiated-type, small-sized carcinomas might have merely failed to be found in routine gastric examination.

Age Factors↗

PubMed1993

Time trend of patient setup deviations during pelvic irradiation using electronic portal imaging.

An electronic portal imaging device (EPID) was used to detect patient setup displacement during the course of a 3-field pelvic irradiation of two groups of patients: 10 rectal and 10 prostate carcinomas. These patients were irradiated with conventional treatment techniques in routine clinical practice. A total of 469 portal images and 60 simulator films were used to determine the values of setup deviations in the X- Y- and Z-directions of a fixed coordinate system, corresponding to the medio-lateral, cranio-caudal and antero-posterior direction, respectively. The absolute displacement averaged over all setups and patients ranged between 0.4 mm and 1.4 mm with a standard deviation (S.D.) of 1.6-3.9 mm. The overall distribution along each direction could be separated into a distribution of random deviations (S.D.s ranging from 1.2 to 2.8 mm) around the mean deviation of each patient and a distribution of the means themselves: the distribution of systematic deviations (S.D.s ranging from 1.0 to 2.6 mm). Significant gradual displacement as a function of time was detected in 5 out of the 20 patients, 2 in the rectum and 3 in the prostate group. This "time trend" was found along each of the 3 directions specified. The magnitude of the time-dependent displacement throughout the course of treatment ranged between 4 and 11 mm. It can be concluded that for treatments requiring a high level of precision, portal images should be made and analyzed during the whole treatment course in order to detect and correct significant time trends.

Carcinoma↗

PubMed1995

Time trends in the care-based incidence of schizophrenia.

BACKGROUND: Several studies have suggested a declining first-admission rate for schizophrenia. This study examines the care-based incidence of schizophrenia in a Dutch register area. METHOD: Data from Groningen psychiatric case register were used to compare first-admission rates for schizophrenia over 1976-90 with those of other functional psychoses, and to consider various potential biases. RESULTS: Diagnostic habits probably affected time trends in incidence rates. Using a broader definition of schizophrenia, no evidence was found for a decrease in the incidence of schizophrenia. Although first admissions to intramural services showed a (non-significant) decrease, this effect seemed to be neutralised when all mental health services were taken into account. CONCLUSIONS: Care-based studies of time trends in psychiatric disorders should embrace all mental health services. Furthermore, unless a diagnostic classification system with univocal criteria is used, bias caused by changing diagnostic habits cannot be ruled out.

Hospitalization↗

PubMed2007

Cellular telephone use and time trends in brain tumour mortality in Switzerland from 1969 to 2002.

A rising concern exists that with the widespread use of mobile communication technologies, the incidence of brain tumours may increase. On the basis of data from the Swiss national mortality registry from 1969 to 2002, annual age-standardized brain tumour mortality rates per 100,000 person-years were calculated using the European standard population. Time trend analyses were performed by the Poisson regression for six different age groups in men and women separately. The study period was divided into two intervals: before and after 1987, when the analogue mobile technology was introduced in Switzerland. Age-standardized brain tumour mortality rates ranged between 3.7 and 6.7 for men and 2.5 and 4.4 for women per 100,000 person-years. For the whole study period, a significant increase in brain tumour mortality was observed for men and women in the older age groups (60-74 and 75+ years) but not in the younger ones in whom mobile phone use was more prevalent. Time trend analyses restricted to data from 1987 onwards revealed relatively stable brain tumour mortality rates in all age groups. For instance, the annual change in brain tumour mortality rate for the 45-59-year age group was -0.3% (95% confidence interval: -1.7; 1.1) for men and -0.4% (95% confidence interval:-2.2; 1.3) for women. We conclude that after the introduction of mobile phone technology in Switzerland, brain tumour mortality rates remained stable in all age groups. Our results suggest that mobile phone use is not a strong risk factor in the short term for mortality from brain tumours. Ecological analyses like this, however, are limited in their ability to reveal potentially small increases in risk for diseases with a long latency period.

Adolescent↗

PubMed1993

The time trend and age-period-cohort effects on incidence of adenocarcinoma of the stomach in Connecticut from 1955-1989.

BACKGROUND: Adenocarcinoma of the gastric cardia has been be increasing in Connecticut, and the risk factors responsible for the increasing incidence are unknown. This study examined the incidence pattern of adenocarcinoma of the gastric cardia and distal stomach in Connecticut during the past decades and identified components of birth cohort, period, and age as determinants of the observed time trends by regression modeling. METHODS: This study was based on all histologically confirmed incident cases of gastric adenocarcinoma reported to the Connecticut Tumor Registry between 1955 and 1989. Stomach cancers were grouped into cancers of the gastric cardia, distal stomach, or unknown/unspecified subsite. Age-adjusted incidence rates were calculated by the direct method standardized to the 1970 United States population. A regression model was used to identify birth cohort, period, and age as determinants of the observed time trends. RESULTS: The results indicated that the incidence rate of adenocarcinoma of the cardia is increasing, particularly in white males, whereas adenocarcinoma of the distal stomach is now decreasing in both sexes in Connecticut. Regression modeling suggests that the increase of adenocarcinoma of the cardia may be explained partly by a birth cohort phenomenon. CONCLUSION: There is little information regarding the risk factors that might be responsible for the observed increasing trend for adenocarcinoma of the cardia, although smoking, alcohol intake, retinol intake, and hiatal hernia have been associated with an increased risk of adenocarcinoma of the cardia or gastric cancer. Considering the different epidemiologic features of adenocarcinoma of the cardia and distal stomach, future analytic studies should separate cancer of the gastric cardia and cancer of the distal stomach in searching for etiologic factors.

Adenocarcinoma↗

PubMed1975

[On cancer mortality in the German Democratic Republic. Regional differences and time trends of mortality of malignant neoplasms of stomach, colon, rectum, breast, and uterus, 1960--1969].

Mortality of maligant neoplasms of stomach (ICD 151; 84 529 deaths), colon (ICD 153; 13237 deaths), rectum (ICD 154; 13687 deaths), breast (ICD 174; 24400 deaths), and uterus (ICD 180--182; 25308 deaths) in the GDR in the years from 1960 to 1969 is described. There are regional differences of mortality which cannot be explained by demographic and diagnostic factors solely but suggest that there exist real differences of cancer risk. Mortality of stomach cancer is relatively low in the middle regions (Berlin, Frankfurt, Potsdam, Cottbus) and in the region of Erfurt and remakably high in the regions of Schwerin, Neubrandenburg, Gera, Leipzig and Karl-Max-Stadt. Mortality of colonic cancer is highest in Berlin, lowest in Schwerin, Neubrandenburg and Gera. Mortality of rectum cancer shows minor regional differences and another distribution than colonic ancer. Mortality of breast cancer is extremely high in Berlin and very low in Suhl. Mortality of cancer of the uterus reaches high levels in Neubrandenburg and is very low in the region of Karl-Marx-Stadt. In the period 1960--1969, mortality of stomach cancer has decreased whereas mortality of colonic cancer has increased. Mortality of rectum neoplasm remained constant. The time trend of mortality of breast cancer demonstrates regional differences and has increased somewhat in th GDR. Mortality of uterus cancer has slightly decreased. Regional differences and time trends of cancer mortality in the GDR suggest the influence of environmental factors.

Adolescent↗

PubMedDate not supplied

Time trends of benign/malignant breast biopsy ratios a multicenter Italian study.

AIMS AND BACKGROUND: Although they have been decreasing over time due to improved specificity of diagnostic assessment, benign biopsies of the breast are still common. Benign biopsies should be regarded as negative events, due to their economical and psychological cost and their possible negative impact on cosmesis and on further diagnostic evaluation. METHODS: Retrospective data on benign/malignant breast biopsies ratio (B/M) were collected in 9 Italian centers for a period of 10-15 years. The time trend of B/M and its association to age or to single centers was evaluated. RESULTS: Overall 31,001 cases were considered. A strong association of B/M to age was evident (average B/M values were 5.0, 1.3, 0.6, and 0.2 for women aged < 40, 40-49, 50-59, and > 59 years). A significant trend of decreasing B/M over time was observed only for one center. Age standardized B/M was significantly different (P < 0.000001) between centers, ranging between 0.34 and 1.69. Multivariate analysis confirmed an independent significant association of age and center to B/M. CONCLUSIONS: Marked differences in B/M are evident between centers, which cannot be explained by the confounding effect of age or by any apparent difference in the diagnostic protocol. The observed differences are likely ascribed to individual variations in diagnostic aggressivity. A progressive increase of the predictive value of calls for surgical biopsy may be achieved over time and centers with a high B/M should make every effort to optimize their performance. Acceptable (< 40 = 5, 40-49 = 1.5, 50-59 = 0.75, > 59 = 0.3) and desirable (2.5, 0.75, 0.35, 0.15) age specific reference standards for B/M are proposed.

Adult↗

PubMed1998

Time trends in HIV infection among pregnant women in Europe.

OBJECTIVE: To estimate time trends in HIV prevalence among pregnant women delivering livebirths in 14 European countries using a uniform methodology. METHODS: A form of back-projection was used to estimate HIV prevalence among pregnant women based on reported cases of AIDS due to perinatally acquired HIV infection. The method used estimates the rate of progression to AIDS in children with HIV, and the rate of transmission of HIV from mother to child, derived from published studies. RESULTS: The prevalence of HIV among pregnant women delivering livebirths was estimated to be highest in Spain (2.61 per 1000 livebirths in 1992-1993), relatively high (> or = 0.3 per 1000 livebirths) throughout the period 1984-1993 in France, Italy and Switzerland, and low (< 0.2 per 1000 livebirths) in Germany, The Netherlands and Scandinavia. There were large and statistically significant increasing trends in the estimated HIV prevalence among pregnant women in Portugal (an estimated 77% increase per 2-year period), Spain (40% increase) and the United Kingdom (77% increase; all P < 0.001). Statistically significant increasing trends of a smaller magnitude were estimated for France (24% increase) and Italy (23% increase; both P < 0.001). CONCLUSIONS: Sharp increases in HIV prevalence among pregnant women were estimated for several European countries, whereas in other countries no trends in the estimated prevalence were detected.

Adolescent↗

PubMed1992

Time trends of HBsAg prevalence among blood donors in Fukuoka, Japan.

We examined time trends of the prevalence of hepatitis B surface antigen (HBsAg) among blood donors at the Fukuoka Red Cross Blood Center, Japan, during 1977-88. As was expected, a marked but artificial decrease in the HBsAg prevalence attributable to a notification program was detected. The seropositivities among males were uniformly higher than those among females. About 1% absolute rate decrease (approximately 50% relative rate reduction) was found among young donors aged 16-19 in seven years before the notification schedule. An age effect closely related to self-selection due to chronic hepatitis B virus (HBV) infection was demonstrated in the declining trends according to the advance of age. A remarkable birth cohort effect was also observed for both sexes. These data undoubtedly indicate that there were medical/iatrogenic factors as well as natural (sanitary/socioeconomic/nutritional) factors causing the reduction of chronic HBV infection.

Adolescent↗

PubMedDate not supplied

Time trends of occupational pesticide-related injuries in Costa Rica, 1982-1992.

To evaluate time trends of occupational pesticide-related injuries in Costa Rica, a survey was carried out three times over a ten-year period at a national reporting system for occupational accidents and diseases among wage-earning workers. The sample comprised the accidents reported during the months of June of the years 1982, 1987, and 1992. The overall incidence rates were 1.8, 2.7, and 2.5 per 1,000 agricultural workers, respectively. Rates among female workers increased (3.1, 3.7, 5.4) and were elevated as compared with male workers (1.7, 2.6, 2.3). The trend for topical lesions was upgoing (1.2, 1.4, 2.1), consistent with an increased use of fungicides and lack of safety measures for pesticides with low acute toxicity. Systemic poisonings peaked in 1987 (0.6, 1.2, 0.5), declining in 1992 with increased use of biologic pest control and pyrethroid insecticides less toxic than cholinesterase inhibitors, and improved safety during nematocide applications on banana plantations. In 1992, despite the largest decline of systemic poisonings in the banana-producing Atlantic Region, poisonings as well as topical injuries were still four times more frequent in this region than in the rest of the country. Restriction of highly toxic pesticides together with implementation of occupational safety measures can reduce systemic poisonings in developing countries. Such policies need to be extended to other pesticides to prevent less life threatening but often disabling skin and eye injuries.

Accidents, Occupational↗