Hypothesis Testing On Suicide

Hypothesis Test on Suicide

Hypothesis Test on Suicide

Suicide is a serious public health problem that devastates individuals, families, and communities. It is defined as taking one's own life. Suicide behavior is complex. National Vital Statistics Report shows suicide is the 11th leading cause of death among Americans (CDC, 2004). Suicide results from complex interactions between biological, psychological, social, and environmental factors. In this study, numbers of suicide death were examined on the U.S. Mortality Report from 1998 to 2005 (CDC, 2004). The hypothesis suggested whether the yearly mean number of suicide death is more than 26,000. The final statistical analysis indicated that this hypothesis was not rejected because it was below the upper critical value, nor could we support the claim that the mean mortality rate of suicide has increased. This report shall describe A-Team's selection. The report shall discuss type of method used and formulate both a numerical and verbal hypothesis statement regarding our research issue and perform the five-step hypothesis test on data pertaining to our selection. Finally the report shall describe the results of this test and explain how the use of hypothesis test can be used to evaluate solutions to the problem. The findings indicate a substantial increase in homicide rates among young males from 2002 to 2003 and substantial increases in both homicide and suicide rates among males from 2000 to 2003. Research over the past several decades has uncovered a wealth of information on the causes of suicide and the strategies to prevent it. Many studies have identified factors that either increase or reduce the likelihood that a person will attempt or commit suicide. Centers for Disease Control and Prevention and National Center (CDC) used this information to develop and implement prevention programs to reduce the numbers of attempted and completed suicides. The results of the analysis indicate that involvement in risky activities is highly correlated with teen suicide attempts. In particular, teens that use drugs and are sexually active are more likely to attempt suicide. Since these behaviors are most likely engaged in by teens with high future discounting, these results are consistent with the hypothesis that suicide attempts are rational. Unhappiness, as reflected here by dissatisfaction with weight, is at higher risk for 13 attempting suicide. Evidence that most attempts are planned and not just acts of passion provides further support for the rational theory.

Method

Secondary data were retrieved from the National Mortality Survey (NMS) (CDC, 2004). The data were released in 1998 with identifying information which were redacted to aid analyses. The National Mortality Survey represents an 8-year collaborative project between the National Center for Health Statistics (NCHS) and several federal agencies, state and local governments, colleges and university, and private associations and organizations. The survey was the sixth in NCHS in the early 1960s to provide additional information related to mortality in the United States beyond that obtained through the registration of deaths. NMS was based on a sample of 22,957 death certificates from 2,215,000 individuals aged 15 years and older who were residing and died in the United States. Death certificates were drawn from the 1993 Current Mortality Sample, a 10% systematic sample of death certificates received at the NCHS from state vital statistics offices. To produce more vigorous analysis of predictors of death from violent causes, the NMS over-sampled certain causes of death (e.g. suicide, homicide) and certain age groups. NMS have trained personnel contact the decedent's next of kin by telephone or in person and asked them to participate in the survey and provide information on the decedent. Written consents was obtained prior to in person interviews.

Null hypothesis, alternate hypothesis, and level of significance

The null hypothesis is that the population mean is at least 26,000. The alternate hypothesis is that the population mean is greater than 26,000. The null and alternate hypothesis is expressed as follows:

1. Ho:Ð'µ≤ 26,000

2. Ho:Ð'µ>26,000

We used the one-tailed because to determine whether there has been an increase in suicide death. The inequality in the alternate hypothesis points to the region of rejection in the right tail of the distribution. The team decided on the .05 significance level.

Test statistic

As the sample size is large and the population standard deviation is known, the sample mean is normally distributed with expectation and standard deviation. Hence, the statistic

X-Ð'µ/σ/√n has a standard normal distribution. Therefore, Z-test statistic was used.

Formulate decision rule

The decision rule is formulated by finding the critical values of z. Because the alternate hypothesis states a direction, a one-tailed test is applied. The standard deviation of the population is identified as 2,000. The critical value of z is 1.65. The computed value of z is .58. A table chart is included. The decision rule is as follows:

z = 26,408-26,000/2,000/√8 = .58

Table 1

Microsoft Excel table on Decision Rule Formula. Rejection Region for the .05 Level of Significance, One Tailed Test.

Year Suicide deaths Total mean Population standard

1998 30575 211,2666/8 = 26,408 2,000