Question

what are some specific ways normal distribution is used and also, misused in healthcare?

Answer 1

Uses of Normal Distribution in health cone Researches investigated whether antidepressant du pusotibing and meermals to secialist Series for depress you by general practions were associated with batient's scores on depression severity questionnaires measured at the start of the treatment. Anonymised data from the medical as of 38 general boeties were investigated. The nine item batient health questionnaire (PH G-1) was used on 1658 batients and the departo Qubscale of the hospital anxiety and OP seale (HABS) was used in 548 patients The distribution of HADS questionnaire scores for the sample was atbrocimately norma whereas the PHQ-9 scores worse regetively The mean was 15.5 of PHQ-9 and standan deviation was 6.0. The moon HA DS score te and B.d won 4.6. It was reported that patients with higher depression severity scomes were more Lately to receive prescriptions en antidepressants and be referred to specialist services. However, other factores" were independently associated with treatment and refermal, including patient age and concorrent physical thers and geographical arcoat It is often the case with medical data that the histogram of a continioue variable obtained from a single measurement on different subjects will have a characteristic cbell-shaped distribute known as a normal distribution. One such example is the westogram of the birth weight (in kilograms) of the 3.226 new born babies shown in the following figuree.

10+ 3007 Beagleancy 2007 N = 3,296 mean = 3.37 kg. S.D=0.55 kg 100 1.00 2.00 3.654 00 500 600 Birth weight (relograms) a To distinguish the use of the same word en normal range and Normal distribution we have used a lower and uppet care convention thoroughout. The histogram of the sample data is an estimate of the population distribution of birth weights in new born babies. This population distribution can be estimated by the superimposed mooth ben-&habedeutne or Normal uton hon. We pronume that I we were able to look at the entire population of new born babees them the distribution of berth weight would have exactly the Normal shape. we often infer, from a sample whose histogroom. has the approximate Normal shape, that the population will have exo or al nor a makes me practical difference, that normal shape. A baby's weight at birth is strongly with mortality risk duver ng the first year and, toa clerser dogree with developmental problems in childhood and the rest of various diseases in adulthard. Normal distributio concerns quorfitative Votiable eng systolic BP, birth weights, age at menarche eto observations of a quantitative variable like systolic BP have been taken from a large random varcelable, a fragriency distribution table has to be prepared ring class or group intervals.

Systolic BP Pergreeney 60-70 70-80 80-90 Systolic BP - 150-160 Freq. 99 90-100 90 100-110 194 to-120 453 160-170 16 120-130 199 130-140 134 Tuo - ISO 10-0 A histogram om es represented is represented of these data. The of the frequencies of the class intervals are platted againt the intervals on a graph. Frequency # GO + so 90 100 110 120 130 140 150 160 class boundaries By defining & ining normal we run the risk of wrongly excluding sl. of heald healthy subjects as abnorgnal but they have only 5% chance of being normal, nence should be thoroughly worked up to the sull out any disease.

- W Mesuse of Normal Distribution in health care. With the growth of clinical rescasch, data, analyses have become incrisingly complicated. Despite advancements in staties, a large proportion of Surgical research analyse's he's not adopted appropriate statistical testing methods as indicated for the type of data researched Although complex statistical models are available to use may data boses are not normally distributed yet basic parametric statistics continue 10 to be used at a seemingly high rate (60%) within sewegical literature. Instead, non-parametric tests are the approbareate choice for non normally distributed data.

Another common mestake is to assume statistical tests of normality werle tests for! normality, and to interpret a outcome a régnéficant accordingly. tontt on stresseoranbod guy Du