A meta-analysis of 61 sperm count studies revisited

Stan Becker; Kiros Berhane

doi:10.1016/S0015-0282(97)81446-X

A meta-analysis of 61 sperm count studies revisited

Stan Becker, Kiros Berhane

Bloomberg School of Public Health

Research output: Contribution to journal › Article › peer-review

Abstract

Objective: To re-examine data on sperm counts over time from 61 studies from around the world. Design: Parametric analyses and flexible nonlinear models of the relation between sperm counts and time. Main Outcome Measure(s): Mean sperm concentrations per milliliter and regression coefficients for possible trends of concentrations over time. Result(s): A significant decline was found only in U.S. studies. Conclusion(s): Studies from specific sites have found declines in sperm counts, but a world-wide decline has not been demonstrated. Rigorous assessment of statistical models should be done before conclusions are drawn. Flexible smoothing models are a useful addition to currently available analytic methods.

Original language	English (US)
Pages (from-to)	1103-1108
Number of pages	6
Journal	Fertility and sterility
Volume	67
Issue number	6
DOIs	https://doi.org/10.1016/S0015-0282(97)81446-X
State	Published - Jun 1997

Keywords

Mean sperm counts
Meta-analysis
Statistical modeling

ASJC Scopus subject areas

Reproductive Medicine
Obstetrics and Gynecology

Access to Document

10.1016/S0015-0282(97)81446-X

Fingerprint Dive into the research topics of 'A meta-analysis of 61 sperm count studies revisited'. Together they form a unique fingerprint.

Cite this

@article{97c7b532e94c41f7b70df5c74f2cc3cb,

title = "A meta-analysis of 61 sperm count studies revisited",

abstract = "Objective: To re-examine data on sperm counts over time from 61 studies from around the world. Design: Parametric analyses and flexible nonlinear models of the relation between sperm counts and time. Main Outcome Measure(s): Mean sperm concentrations per milliliter and regression coefficients for possible trends of concentrations over time. Result(s): A significant decline was found only in U.S. studies. Conclusion(s): Studies from specific sites have found declines in sperm counts, but a world-wide decline has not been demonstrated. Rigorous assessment of statistical models should be done before conclusions are drawn. Flexible smoothing models are a useful addition to currently available analytic methods.",

keywords = "Mean sperm counts, Meta-analysis, Statistical modeling",

author = "Stan Becker and Kiros Berhane",

year = "1997",

month = jun,

doi = "10.1016/S0015-0282(97)81446-X",

language = "English (US)",

volume = "67",

pages = "1103--1108",

journal = "Fertility and Sterility",

issn = "0015-0282",

publisher = "Elsevier Inc.",

number = "6",

}

TY - JOUR

T1 - A meta-analysis of 61 sperm count studies revisited

AU - Becker, Stan

AU - Berhane, Kiros

PY - 1997/6

Y1 - 1997/6

N2 - Objective: To re-examine data on sperm counts over time from 61 studies from around the world. Design: Parametric analyses and flexible nonlinear models of the relation between sperm counts and time. Main Outcome Measure(s): Mean sperm concentrations per milliliter and regression coefficients for possible trends of concentrations over time. Result(s): A significant decline was found only in U.S. studies. Conclusion(s): Studies from specific sites have found declines in sperm counts, but a world-wide decline has not been demonstrated. Rigorous assessment of statistical models should be done before conclusions are drawn. Flexible smoothing models are a useful addition to currently available analytic methods.

AB - Objective: To re-examine data on sperm counts over time from 61 studies from around the world. Design: Parametric analyses and flexible nonlinear models of the relation between sperm counts and time. Main Outcome Measure(s): Mean sperm concentrations per milliliter and regression coefficients for possible trends of concentrations over time. Result(s): A significant decline was found only in U.S. studies. Conclusion(s): Studies from specific sites have found declines in sperm counts, but a world-wide decline has not been demonstrated. Rigorous assessment of statistical models should be done before conclusions are drawn. Flexible smoothing models are a useful addition to currently available analytic methods.

KW - Mean sperm counts

KW - Meta-analysis

KW - Statistical modeling

UR - http://www.scopus.com/inward/record.url?scp=0030961755&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030961755&partnerID=8YFLogxK

U2 - 10.1016/S0015-0282(97)81446-X

DO - 10.1016/S0015-0282(97)81446-X

M3 - Article

C2 - 9176451

AN - SCOPUS:0030961755

VL - 67

SP - 1103

EP - 1108

JO - Fertility and Sterility

JF - Fertility and Sterility

SN - 0015-0282

IS - 6

ER -