Bibliography Tag: trends analysis

Blair and Zahm, 1993

Blair, A., & Zahm, S. H.; “Patterns of pesticide use among farmers: implications for epidemiologic research;” Epidemiology, 1993, 4(1), 55-62; DOI: 10.1097/00001648-199301000-00011.


Epidemiologic studies of farmers have linked pesticides with certain cancers. Information on exposures from many of these studies was obtained by interview of farmers or their next-of-kin. The reliability and validity of data on pesticide use obtained by recall, often years after the event, have been questioned. Pesticide use, however, is an integral component in most agricultural operations, and the farmers’ knowledge and recall of chemicals used may be better than for many other occupations. Contrary to general belief, many farmers typically use only a few pesticides during their lifetimes and make only a few applications per year. Data from U.S. Department of Agriculture surveys indicate that herbicides are applied to wheat, corn, soybeans, and cotton and that application of insecticides to corn averages two or fewer times per year. In epidemiologic studies at the National Cancer Institute, the proportion of farmers ever reporting lifetime use of five or more different chemicals was 7% for insecticides and 20% for herbicides. Surrogate respondents have often been used in epidemiologic studies of cancer; they are able to recall pesticide use with less detail than the farmers themselves. The pesticides reported by surrogates were the same as reported by subjects themselves, but with less frequency. Comparison of reporting by cases and controls provided no evidence of case-response (differential) bias; thus, inaccurate recall of pesticide use by subjects or surrogates would tend to diminish risk estimates and dilute exposure-response gradients. FULL TEXT

Potera, 2015

Potera, C.; “Tracking organophosphates: new method for assessing long-term dietary exposures;” Environmental Health Perspectives, 2015, 123(5), A135; DOI: 10.1289/ehp.123-A135.


Not Available


Sharma and Peshin, 2016

Sharma, Rakesh, & Peshin, Rajinder; “Impact of integrated pest management of vegetables on pesticide use in subtropical Jammu, India;” Crop Protection, 2016, 84, 105-112; DOI: 10.1016/j.cropro.2016.02.014.


In a study at the subtropical vegetable-growing areas of the state of Jammu and Kashmir (J&K), a quasi-experimental research design with a non-equivalent control group was employed to examine the impact of an integrated pest management (IPM) program implemented from 2008 to 2010 on the adoption of non-chemical pest management practices, pesticide use by weight (active ingredient [a.i.]), pesticide use frequency, field use environment impact (FEIQ) and safe handling and application of pesticides by IPM-trained farmers. There was no significant change in adoption of non-chemical practices, other than pheromone traps used by okra (Abelmoschus esculentus (L.) Moench) growers. Growers reduced FEIQ by 17.9 per hectare from 2008 to 2010. Pesticide use (a.i.) did not decrease significantly, and frequency decreased significantly by 72.4% only in cauliflower (Brassica oleracea L. var. botrytis). The vegetable growers did not use protective equipment while handling and applying pesticides thus putting themselves at risk. Implementation of IPM thus needs to be reexamined to significantly reduce pesticide use by weight, treatment frequency and FEIQ.

Levine et al., 2017

Levine, H., Jorgensen, N., Martino-Andrade, A., Mendiola, J., Weksler-Derri, D., Mindlis, I., Pinotti, R., & Swan, S. H.; “Temporal trends in sperm count: a systematic review and meta-regression analysis;” Human Reproduction Update, 2017, 23(6), 646-659; DOI: 10.1093/humupd/dmx022.


BACKGROUND: Reported declines in sperm counts remain controversial today and recent trends are unknown. A definitive meta-analysis is critical given the predictive value of sperm count for fertility, morbidity and mortality.

OBJECTIVE AND RATIONALE: To provide a systematic review and meta-regression analysis of recent trends in sperm counts as measured by sperm concentration (SC) and total sperm count (TSC), and their modification by fertility and geographic group.

SEARCH METHODS: PubMed/MEDLINE and EMBASE were searched for English language studies of human SC published in 1981-2013. Following a predefined protocol 7518 abstracts were screened and 2510 full articles reporting primary data on SC were reviewed. A total of 244 estimates of SC and TSC from 185 studies of 42 935 men who provided semen samples in 1973-2011 were extracted for meta-regression analysis, as well as information on years of sample collection and covariates [fertility group (‘Unselected by fertility’ versus ‘Fertile’), geographic group (‘Western’, including North America, Europe Australia and New Zealand versus ‘Other’, including South America, Asia and Africa), age, ejaculation abstinence time, semen collection method, method of measuring SC and semen volume, exclusion criteria and indicators of completeness of covariate data]. The slopes of SC and TSC were estimated as functions of sample collection year using both simple linear regression and weighted meta-regression models and the latter were adjusted for pre-determined covariates and modification by fertility and geographic group. Assumptions were examined using multiple sensitivity analyses and nonlinear models.

OUTCOMES: SC declined significantly between 1973 and 2011 (slope in unadjusted simple regression models -0.70 million/ml/year; 95% CI: -0.72 to -0.69; P < 0.001; slope in adjusted meta-regression models = -0.64; -1.06 to -0.22; P = 0.003). The slopes in the meta-regression model were modified by fertility (P for interaction = 0.064) and geographic group (P for interaction = 0.027). There was a significant decline in SC between 1973 and 2011 among Unselected Western (-1.38; -2.02 to -0.74; P < 0.001) and among Fertile Western (-0.68; -1.31 to -0.05; P = 0.033), while no significant trends were seen among Unselected Other and Fertile Other. Among Unselected Western studies, the mean SC declined, on average, 1.4% per year with an overall decline of 52.4% between 1973 and 2011. Trends for TSC and SC were similar, with a steep decline among Unselected Western (-5.33 million/year, -7.56 to -3.11; P < 0.001), corresponding to an average decline in mean TSC of 1.6% per year and overall decline of 59.3%. Results changed minimally in multiple sensitivity analyses, and there was no statistical support for the use of a nonlinear model. In a model restricted to data post-1995, the slope both for SC and TSC among Unselected Western was similar to that for the entire period (-2.06 million/ml, -3.38 to -0.74; P = 0.004 and -8.12 million, -13.73 to -2.51, P = 0.006, respectively).

WIDER IMPLICATIONS: This comprehensive meta-regression analysis reports a significant decline in sperm counts (as measured by SC and TSC) between 1973 and 2011, driven by a 50-60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand. Because of the significant public health implications of these results, research on the causes of this continuing decline is urgently needed.