Hello, I am currently in a well-regarded program in statistics. Biostatistics is mainly about applied statistics related to the four phases of clinical trials which determine whether a drug is going to be approved by the FDA. This type of work is conducted in pharmaceutical companies, research institutions, and large medical centers. Also, statistical anaylsis of genomics data (bioinformatics) is a sub-branch of biostatistics. There is not much science in this field that is mostly based by applied mathematics. The exception would be in the statistical genetics area where you would have to be familiar, with Population and Molecular Genetics (which could be taken while in the graduate program).
The masters program involves courses in statistical theory (see Casella and Berger's Statistical Inference) and applied methods (such as design of experiments) and courses in linear models (basically linear algebra applied to appied regression techniques such as ANOVA, ANCOVA, etc). The basic mathematical prerequisites are multivariate calculus (calculus III), linear algebra, and an undergraduate probability course (calculus based).
If you go for the PhD, the courses become tough. Your core courses include measure theory (this is in regards to Lebesgue vs. Riemann integrability, Kolgomorov Zero-One Laws). This sequence assumes you have a two-semester sequence in mathematical analysis which many schools would allow you to make up if you were deficient in this (this is an undergrad course taught for mathematics majors which essentially proves every theorem that you learned in your three semesters of calculus). (Check Bartle and Sherbert Real Analysis for the first semester or a book such as Rudin's mathematical analysis) This being said, some PhD courses such as measure theory, while very interesting, are only useful in a pure academic setting. In mos cases, the jobs in the pharmaceutical industry will be related more to linear models and ANOVA regression than to probability theory with a few exceptions.
This being said, most pharmaceutical companies mainly hire PhDs in statistics or biostatistics and not too many masters students. In fact finding internships for the pharmaceutical companies are a LOT MORE COMPETITIVE than gaining admission to some of the more difficult pharmacy schools. Out of 120 grad students in my department, only about 8 found summer internships, even though my school is located in a very lucrative area for those types of jobs. And internship experience is quite critical in finding a good job (that is unless you have a very good PhD advisor). This highl level of competition is due to the fact the most statistics/biostatistics departments have over 50% international students mainly from China and India who have significant working experience and very strong training even before they come here. Moreover, many of these students are extremely strong mathematically even if their major was biology or life science. Furthermore the American students are also very strong as well.
The American students in my school are from Cal Poly, Brigham Young University, Missouri, SUNY-Stony Brook, Mississippi State, Virginia Tech and other schools and have an average of around a 3.7-3.8 undergrad GPA. They have majored in such various fields including psychology, statistics, mathematics, electrical engineering, computer science, molecular biology, neuroscience. The most common majors, of course, are statistics and mathematics. I had a 3.987 GPA in statistics at my undergrad school, and this is not uncommon at all. In fact there are a few straight 4.0 students such as the student from Southern miss / Mississippi State. One Indian student had even worked at Pfizer in India for two years before coming to my school. Some other Chinese students had already completed medical residencies and there is also a Chinese girl with a degree in dentistry who won an internship at Merck. And one of my classmates in the master of statistics even has a PhD in physical chemistry from Peking University (equivalent to Harvard University in China) and cannot find a tenured faculty job (he is a postdoc at my school). So he is trying to earn the masters of statistics to hopefully find a decent job.
Now that being said the BIOSTATISTICS departments in Schools of Public Health, such as UNC-Chapel Hill, University of Washington, Emory, Johns Hopkins, Harvard, are different from STATISTICS departments in that they only focus on the pertinent area applied to clinical trials or statistical genetics. A stat department like the one that I am in would have faculty involved in biostatistics but would not be solely focused on that but on all areas of statistics such as environmental statistics, mathematical statistics, financial statistics, etc. The departments in the Schools of Public Health tend to be affiliated with a hospital or medical center.
I personally think unless you really like matematics/statistics more than the science, stick to professional school or maybe consider a biomedical science PhD, if scientific research interests you.
For your information, the average starting salary with a masters degree is $50,000 and with a doctorate the range is from $65,000-90,000. I think that the $80,000-90,000 would be paid by the big pharmaceutical companies located in higher cost of living areas such as Merck, Bristol-Myers Squibb. The $65,000-75,000 would be paid by smaller contract research organizations. So I would say the average starting salary is around $75,000 with PhD. If you have several years of working experience at a major pharmaceutical company along with a PhD, you could easily earn around $100,000. The highest starting salaries with a PhD that I know of is one students salary at Eli Lilly around $80,000 another salary at Bristol Myers Squibb at around $83,000.
If you are able to win a job, the salary is quite good, but the competition is quite fierce.
One note, most schools give out stipends and tuition waivers, with a few exceptions.
