In a statistical analysis, the process of manipulating or stratifying the values of independent variables so as to minimize their confounding influence on the relationship or association between an independent variable of interest and the dependent variable.
Ambulatory-care-sensitive condition (ACSC)
A preventable or avoidable hospitalization; a research construct used as an indicator of barriers to access to ambulatory care. Certain diagnoses for inpatient episodes are defined as preventable or avoidable if they are responsive to timely and appropriate ambulatory care. Rates of hospitalization above a specified baseline are construed as indicative of inadequate ambulatory care.
A correlation or relationship that may or may not be causal—for example, when events occur more frequently together than one would expect by chance alone.*
Any systematic error in the design, conduct or, analysis of a study that results in a mistaken estimate of an exposure’s effect on the risk of disease (Gordis, 1996).
A relationship that may exist between an exposure or treatment (cause) and an outcome (effect), depending in part on the strength of the association between exposure or treatment and outcome.
A disease that has one or more of the following characteristics: is permanent; leaves residual disability; is caused by nonreversible physiological damage; requires special training of the patient for rehabilitation; or may be expected to require a long period of supervision, observation, or care.*
Confidence interval (CI)
A numeric range estimated with a specific degree of confidence or probability to include a value. Conventionally reported confidence intervals are ranges in which the actual value of the estimated variable can be expected to fall 95 or 99 percent of the time, corresponding to probabilities that a difference or significant result is due to chance of less than 5 percent and 1 percent, respectively (p < .05; p <.01). In reporting quantified results throughout this report (e.g., odds ratios, relative risks), if the confidence interval is not given, point estimates have at least a 95 percent probability of being statistically significant. Confidence intervals are given for findings reported with lesser levels of statistical significance.
A variable that is associated with an exposure or treatment of interest and, as a result, influences the relationship between the exposure or treatment and an outcome. The ability to adjust or analytically control for the presence of a confounder depends on how well this variable is measured.
Any provision of a health insurance policy that requires the insured individual to pay some portion of medical expenses. The general term includes deductibles, copayments, and coinsurance.*
A variable that is related to or associated with the study variable(s) of interest.
Describes a research study in which measurements are collected and comparisons made among populations at one point in time.
A factor, indicator, construct, or other measure of an outcome or effect of interest that is influenced by or dependent on independent variables of interest.
Describes a study design—for example, a randomized clinical trial—where researchers use a defined study population, randomly assign members of the population to exposure or treatment and control groups, control the timing of the exposure or treatment, and influence the timing of measurements.
Family coherence and hardiness
Based on family systems theory, two research constructs that measure resilience to stress, used to analyze the influence of individual and family-level psychosocial resources on the relationship between stress and adverse health and other outcomes. An individual’s sense of coherence (in a family context, often a parent’s) and a family’s hardiness each influence how families respond to stressful circumstances (Svavarsdottir et al., 2000).
A measure of the probability of a disease or an outcome’s occurrence, defined as the number of new cases within a defined time period for a specific population divided by the total number in the population (Gordis, 1996).
A factor, indicator, construct, or other measure that influences a dependent variable of interest or the relationship between an exposure or treatment and the dependent variable.
Describes a research study in which measurements are collected and comparisons made among populations over time.
An approach to the organization and delivery of health services for children that is associated with quality health care. It is defined as a means to ensure that health services are accessible, family-centered, continuous, comprehensive, coordinated, compassionate, and culturally effective (American Academy of Pediatrics, 2002).
Persons who cannot afford needed health care because of insufficient income and/or lack of adequate health insurance. Indigent care consists of health services provided to the poor or those unable to pay. Since many indigent patients are not eligible for federal or state programs, the costs that are covered by Medicaid are generally recorded separately from indigent care costs.*
Multivariable or multivariate analysis
A statistical method to characterize the relationship among at least two independent variables that measure exposures or treatments (e.g., potential causes) and a dependent variable that measures an outcome or effect.
A newly born infant.
The insurance market for products sold to individuals rather than to members of groups. Typically each state regulates its own nongroup market.
Describes a research study with a nonexperimental design, in which researchers gather observations or measurements while not intentionally affecting the conditions of exposure, the treatment of the study population, or the timing of measurements.
Odds ratio (OR)
A comparative measure of the strength of a relationship or association between an exposure or treatment and an outcome for two populations, where the baseline incidence of the outcome in these groups may not be known. For example, if the odds of receiving an immunization are 2:1 in a group of uninsured children (i.e., two of every three children, or 67 percent, receive the immunization) and the odds are 4:1 in a group of children who have insurance (i.e., four of every five insured children, or 80 percent, receive it), the odds ratio of uninsured compared to insured children is 0.5 (2:1/4:1). The OR is not a good estimate of the relative risk (the probability of been immunized in the uninsured group divided by the probability of being immunized in the insured group) because immunization is not a rare event.
Health services delivered to a woman and her newborn in the periods immediately before and after birth, ranging from approximately the twentieth to twenty-eighth week of gestation to the first week or month following birth.
Predictor, independent predictor
In a statistical analysis, an independent variable (e.g., that measures an exposure or treatment) that is shown to be likely to influence or predict the value of a dependent variable (e.g., an outcome).
A measure of how common a disease or condition is within a population, defined as the number of cases in the population at a specified time divided by the number of persons in the population at that same time (Gordis, 1996).
Describes a research study—for example, a natural experiment—whose design combines experimental and nonexperimental aspects. Typically, researchers cannot control the timing of the intervention or exposure whose effects are being measured or the random assignment of a defined group of study subjects, but they can influence the timing of measurements.
A research study in which the members of a defined group of subjects are randomly assigned to at least two groups for the purpose of analysis: a treatment or intervention group and a control group.
Relative risk (RR)
A comparative measure of the strength of a relationship or association between an exposure, intervention, or treatment and an outcome for a defined study population, where the baseline incidence of the outcome is known. It is expressed as the ratio of two risks, namely, the rate of a disease or condition
of interest in the treated portion of the population divided by the rate in an untreated or control portion of the population. A value of one means that the rates in both portions are the same.
A type of study, usually a cohort design, in which historical data are used and outcome data are collected at the time the study begins (Gordis, 1996).
Those providers that organize and deliver a significant level of health care and other related services to uninsured, Medicaid, and other at-risk, lower-income patients (Institute of Medicine, 2000).
Section 1115 waiver (Medicaid)
Section 1115 of the Social Security Act grants the secretary of the Department of Health and Human Services broad authority to waive certain laws relating to Medicaid for the purpose of conducting pilot, experimental or demonstration projects that are “likely to promote the objectives” of the program. Section 1115 demonstration waivers allow states to change provisions of the Medicaid programs, including: eligibility requirements, the scope of services available, the freedom to choose a provider, a provider’s choice to participate in a plan, the method of reimbursing providers, and the statewide application of the program (AHSRHP, 2002).
In research studies, a systematic error in analysis that results when study subjects are not assigned randomly among treatment and control groups.
The insurance market for products sold to groups that are smaller than a specified size, typically employer groups. The size of groups included usually depends on state insurance laws and thus varies from state to state, with 50 employees the most common size (AHSRHP, 2002).
Special health needs
Children who have or are at increased risk for a chronic physical, developmental, behavioral, or emotional condition and who also require health and related services of a type or amount beyond that required by children generally (DHHS, 2001).
See definition of Confidence interval.
Demands made by an individual’s internal environment, or an individual’s or family’s external environment, that upset the functioning balance or homeostasis of the individual or family, potentially affecting physical or psychological wellbeing. Stressors may have negative or positive effects, in part depending on how the affected individual or family member perceives the stress and the responses made to stressful circumstances, for example, in the case of economic hardship (Glanz et al., 1997).
A research construct to measure the synergistic effect of multiple changes on children. It is defined as the presence of at least two of the following circumstances: moving from one state to another; moving to a different home; moving in with another family; at least two changes in employment by a parent or parent’s spouse, at least two changes of school, or a significant decline in the health of the child, its parent, or the parent’s spouse (Moore et al., 2000a).
Women, Infants, and Children (WIC) program
The Special Supplemental Nutrition Program for Women, Infants, and Children, administered by the U.S. Department of Agriculture’s Food and Nutrition Service and operated by the states. WIC programs provide vouchers for purchasing certain types of food and nutrition screening and counseling for eligible persons, usually pregnant and postpartum women, infants, and children under the age of 5 who have been determined to be at risk for inadequate nutrition due to health or dietary problems and who are members of families that earn less than 185 percent of the federal poverty level or who receive other benefits (e.g., food stamps, Medicaid, Temporary Assistance for Needy Families) (USDA, 2002).