Subject socioeconomic status

Among the criteria for selecting subjects with close similarities, socioeconomic status cannot be ignored any more than nutritional status or genetic background. Finally, place of residence and prior occupational pollution exposure may be important. 

The MHPCD, initiated in 1982, is focusing upon the consequences of prenatal use of marijuana, alcohol, and cocaine. The subjects in this high-risk cohort are of low socioeconomic status and just over half are African American. Alterations in growth, cognitive development, temperament, and emotionality have been reported in offspring up to the age of 10 (Goldschmidt et al., 2000). 

Study bias may be selection bias or information bias. Selection bias may occur in the choice of subjects for the study (e.g. exclusion of individuals who are not fluent in a particular language). Selection bias may also result from an individual s reluctance to participate in a study owing to concerns over a perceived exposure, resultant health effect, or educational and socioeconomic status of the participants. Parents who perceive that an exposure in their child s environment may have resulted in an adverse health effect may feel responsible for not protecting their child. Information bias may result from inappropriate classification of the individual study participants or from the information provided. For example, interview bias may result when an interviewer is not blind to the exposure of the test population. Recall bias may result when participants with specific exposures or effects respond differently from those without the specific exposures or effects. 

It seems self-evident that psychiatric disorders have social consequences for the individual. One consequence is truncated education.74 But the degree and nature of the social consequences of psychiatric disorders vary with socioeconomic status poor children with psychiatric disorders are not subject to the same constraints and consequences as children with psychiatric... 

The socioeconomic status (SES) of the infant s family was assessed at three months postpartum with the Hollingshead Four-Factor Index of Social Status (Hollingshead, 1975). The mean SES for families in this sample was 17.1 (SD = 5.4), reflecting the preponderance of single-parent low-income households. At 6 and 12 months, the quality of the infant s domestic environment was assessed with Caldwell and Bradley s Home Observation for Measurement of the Environment (HOME) (Caldwell and Bradley, 1978). The HOME combines interviewers questions with direct observations to yield subscale and total HOME scores. In general, the HOME measures both the parent s responsivity and personal involvement with her infant and the extent to which the physical and temporal environment is stimulating and safe. The mean of the 6- and 12-month HOME scores was calculated for each subject and tested as a potential developmental covariate or confounder in regression analyses. 

Most of our subjects are middle to upper-middle class white infants, for whom socioeconomic status and quality of caregiving are at most only weakly associated with prenatal or postnatal blood lead levels (Bellinger et al, 1985b, 1986b). They do not display the typical association between demographic/ economic risk factors and increased lead exposure seen in most samples. As a consequence, the likelihood of observing a spurious association between elevated lead exposure and poor outcome is lower in this sample than it is in most samples recruited to study the developmental impact of lead. 

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