Prevalence is a statistical concept that is defined as the ratio of the number of cases of a disease or condition at a specific time and the number of individuals in the population. Prevalence is usually expressed as a proportion. Measuring prevalence in the realm of interpersonal violence is a much more complicated endeavor than measuring prevalence of other conditions. In estimating prevalence, there are several approaches that can be used. Some of the most common strategies include phone surveys, official records, screening at agencies or medical centers, and large-scale surveys.
Each of these approaches has strengths and weaknesses. For example, phone surveys are less expensive than face-to-face interviews, but the respondent may be cautious about providing answers if the perpetrator of the violence is in close proximity. Alternatively, phone surveys could provide more accurate data because of the increased anonymity compared to face-to-face interviews.
There are multiple challenges to measuring prevalence of interpersonal violence. These include the following:
1. Violence (particularly within the family) is considered by many to be a private matter and may involve significant embarrassment or shame for the person being questioned. Victims of violence may be hesitant to disclose their experiences, even if they are offered confidentiality.
2. Due to child maltreatment reporting laws, respondents may be cautious about providing information that might trigger a child protection response.
3. Definitions of violence are socially constructed, so the extent to which the person being asked about violence shares the same definitions as the person doing the asking will affect response rates. For example, sometimes self-reported rates of bullying victimization in schools rise after a schoolwide bullying intervention because the children’s definitions of bullying have changed.
4. Prevalence rates depend on the group being used as denominator. For example, among abused children, the prevalence of abusive mothers is higher than abusive fathers for most types of abuse. However, this difference in rates is partly due to the number of female-headed single-family households. Among children with two parent figures, the prevalence of perpetration by a father figure equals or exceeds that of a mother figure.
5. Measuring prevalence from official records is subject to the reporting biases and the policies and practices of the agencies collecting the data. For example, the prevalence of neglectful mothers is much higher than that of neglectful fathers as measured by child protection records. However, these rates reflect practice and policy with respect to which parent is investigated and held responsible for child neglect.
6. There is great debate about measuring objective acts of violence or measuring violence within a particular context. On one hand, measuring objective acts (e.g., hits, kicks, punches) reduces the interpretation bias of a particular individual. On the other hand, measuring the context (e.g., severity, impact, perpetrator’s intent) may provide critical information about the violence experienced. This dilemma is a major debate with relation to measuring gender differences in interpersonal violence.
Due to the complexity of measuring the prevalence of interpersonal violence, it is important to evaluate documented rates within the context of the methodology used to obtain them.
