Jun 10, 2015

Healthcare Domain Study Useful links

The below link will be useful.

http://www.healthcareguy.com/wp-content/uploads/2008/03/healthcare-domain.pdf

http://www.technofunc.com/index.php/domain-knowledge/category/healthcare-domain-knowledge

http://www.technofunc.com/index.php/domain-knowledge/insurance-domain

http://anil-businessanalyst.weebly.com/domain-knowledge.html


http://www.businessanalystfaq.com/healthcareknowledgeforba.htm

May 25, 2015

Healthcare Domain Knowledge

Healthcare Domain Knowledge 

Article discuss common healthcare terms from a payer perspective and gives a overview basic HIPAA messages.


Common healthcare terms:
* Payer
* Plan
* Provider
* Member
* Subscriber
* Claim
* Product
* COB (Coordination of benefits)
* PCP (Primary Care Provider)
* Capitation
* HIPAA


Healthcare payer services:


* Revenue Management
* Customer Service
* Product Management
* Consumer Management
* Risk Management
* Care Management
* Provider Management
* Member Management
* Reimbursement Management


Standard Code Sets:

  • ICD-9-CM Diagnosis & Inpatient Procedures
  • CPT-4 Outpatient Procedures
  • HCPCS Ancillary Services & Procedures
  • CDT-2 Dental Terminology
  • NDC National Drug Codes
  • DRG Diagnostic Related Groupings 
ICD-9-CM:
International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM, ICD-10-CM) - This is the universal coding method used to document the incidence of disease, injury, mortality and illness.
A diagnosis and procedure classification system designed to facilitate collection of uniform and comparable health information.
The ICD-9-CM was issued in 1979. This system is used to group patients into DRGs, prepare hospital and physician billings and prepare cost reports.
Classification of disease by diagnosis codified into six-digit numbers. 


Diagnosis Related Groups (DRGs):
An inpatient or hospital classification system used to pay a hospital or other provider for their services and to categorize illness by diagnosis and treatment.


A classification scheme used by Medicare that clusters patients into 468 categories on the basis of patients' illnesses, diseases and medical problems. Groupings of diagnostic categories drawn from the International Classification of Diseases and modified by the presence of a surgical procedure, patient age, presence or absence of significantcomplications/other relevant criteria.


System involving classification of medical cases and payment to hospitals on the basis of diagnosis.


Common Health Plan
 Types:

  • HMO
  • PPO
  • POS
  • Medicaid
  • Medicare
  • Defined Contribution

HMO:
A health maintenance organization (HMO) is a health care delivery system that accepts responsibility and financial risk for providing a specified set of health care services to an enrolled membership in exchange for a fixed, prepaid fee from the purchaser (i.e., either the employer, government or an individual.) HMOs build network through contracts with selected physicians or physician groups, hospitals, and other providers who render care for a given population for a discounted fee in anticipation of an increased volume of patients. Those individuals who become members of an HMO (i.e., enrollees) agree to receive care from this contracted network of providers.
Characterized by a PCP, all treatment/referrals thru PCP

PPO:

Preferred Provider Organization (PPO) is a group of health care professionals and/orhospitals that contract with an employer or insurance company to provide medical care to a specified group of patients. Participating health care providers exchange discounted services for an increased volume of patients from this group. Insurance companies offer PPOs to give their members a choice of either in-network benefits or out-of-network benefits.

May 24, 2015

Best Practices for .Net Coding


Note :
The terms Pascal Casing and Camel Casing are used throughout this document.
Pascal Casing - First character of all words are Upper Case and other characters are lower case.
Example: BackColor
Camel Casing - First character of all words, except the first word are Upper Case and other characters are lower case.
Example: backColor

1.     Use Pascal casing for Class names

public class HelloWorld
{
       ...
}

2.     Use Pascal casing for Method names

void SayHello(string name)
{
       ...
}


3.     Use Camel casing for variables and method parameters

int totalCount = 0;
void SayHello(string name)
{
       string fullMessage = "Hello " + name;
       ...
}

4.     Use the prefix “I” with Camel Casing for interfaces ( Example: IEntity )

5.     Do not use Hungarian notation to name variables.

In earlier days most of the programmers liked it - having the data type as a prefix for the variable name and using m_ as prefix for member variables. Eg:

string m_sName;
int nAge;

However, in .NET coding standards, this is not recommended. Usage of data type and m_ to represent member variables should not be used. All variables should use camel casing.

Some programmers still prefer to use the prefix m_ to represent member variables, since there is no other easy way to identify a member variable.


6.     Use Meaningful, descriptive words to name variables. Do not use abbreviations.

Good:

string address
int salary

Not Good:

string nam
string addr
int sal

7.     Do not use single character variable names like i, n, s etc. Use names like index, temp

One exception in this case would be variables used for iterations in loops:

for ( int i = 0; i < count; i++ )
{
       ...
}

If the variable is used only as a counter for iteration and is not used anywhere else in the loop, many people still like to use a single char variable (i) instead of inventing a different suitable name.

8.     Do not use underscores (_) for local variable names.

9.     All member variables must be prefixed with underscore (_) so that they can be identified from other local variables.

10.  Do not use variable names that resemble keywords.

11.  Prefix boolean variables, properties and methods with “is” or similar prefixes.

Ex: private bool _isFinished

12.  Namespace names should follow the standard pattern

...

13.   Use appropriate prefix for the UI elements so that you can identify them from the rest of the variables.

There are 2 different approaches recommended here.

a.     Use a common prefix ( ui_ ) for all UI elements. This will help you group all of the UI elements together and easy to access all of them from the intellisense.

b.     Use appropriate prefix for each of the ui element. A brief list is given below. Since .NET has given several controls, you may have to arrive at a complete list of standard prefixes for each of the controls (including third party controls) you are using.


Control
Prefix
Label
lbl
TextBox
txt
DataGrid
dtg
Button
btn
ImageButton
imb
Hyperlink
hlk
DropDownList
ddl
ListBox
lst
DataList
dtl
Repeater
rep
Checkbox
chk
CheckBoxList
cbl
RadioButton
rdo
RadioButtonList
rbl
Image
img
Panel
pnl
PlaceHolder
phd
Table
tbl
Validators
val



14.  File name should match with class name.

For example, for the class HelloWorld, the file name should be helloworld.cs (or, helloworld.vb)

15.  Use Pascal Case for file names.




1.     Use TAB for indentation. Do not use SPACES.  Define the Tab size as 4.

2.     Comments should be in the same level as the code (use the same level of indentation).

Good:

// Format a message and display

string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );

Not Good:

// Format a message and display
string fullMessage = "Hello " + name;
DateTime currentTime = DateTime.Now;
string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
MessageBox.Show ( message );

3.     Curly braces ( {} ) should be in the same level as the code outside the braces.

           
4.     Use one blank line to separate logical groups of code.

Good:
       bool SayHello ( string name )
       {
              string fullMessage = "Hello " + name;
              DateTime currentTime = DateTime.Now;

              string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();

              MessageBox.Show ( message );

              if ( ... )
              {
                     // Do something
                     // ...

                     return false;
              }

              return true;
       }

Not Good:

       bool SayHello (string name)
       {
              string fullMessage = "Hello " + name;
              DateTime currentTime = DateTime.Now;
              string message = fullMessage + ", the time is : " + currentTime.ToShortTimeString();
              MessageBox.Show ( message );
              if ( ... )
              {
                     // Do something
                     // ...
                     return false;
              }
              return true;
       }

5.     There should be one and only one single blank line between each method inside the class.

6.     The curly braces should be on a separate line and not in the same line as if, for etc.

Good:
              if ( ... )   
              {
                     // Do something
              }

Not Good:

              if ( ... )    {
                     // Do something
              }

7.     Use a single space before and after each operator and brackets.

Good:
              if ( showResult == true )
              {
                     for ( int i = 0; i < 10; i++ )
                     {
                           //
                     }
              }

Not Good:

              if(showResult==true)
              {
                     for(int          i= 0;i<10 i="" p="">
                     {
                           //
                     }
              }


8.     Use #region to group related pieces of code together. If you use proper grouping using #region, the page should like this when all definitions are collapsed.





9.     Keep private member variables, properties and methods in the top of the file and public members in the bottom. 


1.     Avoid writing very long methods. A method should typically have 1~25 lines of code. If a method has more than 25 lines of code, you must consider re factoring into separate methods.

2.     Method name should tell what it does. Do not use mis-leading names. If the method name is obvious, there is no need of documentation explaining what the method does.

Good:
       void SavePhoneNumber ( string phoneNumber )
       {
              // Save the phone number.
       }

Not Good:

       // This method will save the phone number.
       void SaveDetails ( string phoneNumber )
       {
              // Save the phone number.
       }

3.     A method should do only 'one job'. Do not combine more than one job in a single method, even if those jobs are very small.

Good:
       // Save the address.
       SaveAddress (  address );
      
       // Send an email to the supervisor to inform that the address is updated.
       SendEmail ( address, email );           
      
       void SaveAddress ( string address )
       {
              // Save the address.
              // ...
       }
      
       void SendEmail ( string address, string email )
       {
              // Send an email to inform the supervisor that the address is changed.
              // ...
       }

Not Good:

       // Save address and send an email to the supervisor to inform that
// the address is updated.
       SaveAddress ( address, email );

       void SaveAddress ( string address, string email )
       {
              // Job 1.
              // Save the address.
              // ...

              // Job 2.
              // Send an email to inform the supervisor that the address is changed.
              // ...
       }

4.     Use the c# or VB.NET specific types (aliases), rather than the types defined in System namespace.

       int age;   (not Int16)
       string name;  (not String)
       object contactInfo; (not Object)

               
Some developers prefer to use types in Common Type System than language specific aliases.

5.     Always watch for unexpected values. For example, if you are using a parameter with 2 possible values, never assume that if one is not matching then the only possibility is the other value.

Good:

If ( memberType == eMemberTypes.Registered )
{
       // Registered user… do something…
}
else if ( memberType == eMemberTypes.Guest )
{
       // Guest user... do something…
}
else
{
              // Un expected user type. Throw an exception
              throw new Exception (“Un expected value “ + memberType.ToString() + “’.”)

              // If we introduce a new user type in future, we can easily find
// the problem here.
}

Not Good:

If ( memberType == eMemberTypes.Registered )
{
              // Registered user… do something…
}
else
{
              // Guest user... do something…

// If we introduce another user type in future, this code will
// fail and will not be noticed.
}

6.     Do not hardcode numbers. Use constants instead. Declare constant in the top of the file and use it in your code.

However, using constants are also not recommended. You should use the constants in the config file or database so that you can change it later. Declare them as constants only if you are sure this value will never need to be changed.

7.     Do not hardcode strings. Use resource files.

8.     Convert strings to lowercase or upper case before comparing. This will ensure the string will match even if the string being compared has a different case.

if ( name.ToLower() == “john” )
{
           //…
}

9.     Use String.Empty instead of “”

Good:

If ( name == String.Empty )
{
       // do something
}

Not Good:

If ( name == “” )
{
       // do something
}


10.  Avoid using member variables. Declare local variables wherever necessary and pass it to other methods instead of sharing a member variable between methods. If you share a member variable between methods, it will be difficult to track which method changed the value and when.

11.  Use enum wherever required. Do not use numbers or strings to indicate discrete values.

Good:
       enum MailType
       {
              Html,
              PlainText,
              Attachment
       }

       void SendMail (string message, MailType mailType)
       {
              switch ( mailType )
              {
                     case MailType.Html:
                           // Do something
                           break;
                     case MailType.PlainText:
                           // Do something
                           break;
                     case MailType.Attachment:
                           // Do something
                           break;
                     default:
                           // Do something
                           break;
              }
       }


Not Good:

       void SendMail (string message, string mailType)
       {
              switch ( mailType )
              {
                     case "Html":
                           // Do something
                           break;
                     case "PlainText":
                           // Do something
                           break;
                     case "Attachment":
                           // Do something
                           break;
                     default:
                           // Do something
                           break;
              }
       }
12.  Do not make the member variables public or protected. Keep them private and expose public/protected Properties.

13.  The event handler should not contain the code to perform the required action. Rather call another method from the event handler.

14.  Do not programmatically click a button to execute the same action you have written in the button click event. Rather, call the same method which is called by the button click event handler.

15.  Never hardcode a path or drive name in code. Get the application path programmatically and use relative path.

16.  Never assume that your code will run from drive "C:". You may never know, some users may run it from network or from a "Z:".

17.  In the application start up, do some kind of "self check" and ensure all required files and dependancies are available in the expected locations. Check for database connection in start up, if required. Give a friendly message to the user in case of any problems.

18.  If the required configuration file is not found, application should be able to create one with default values.

19.  If a wrong value found in the configuration file, application should throw an error or give a message and also should tell the user what are the correct values.

20.  Error messages should help the user to solve the problem. Never give error messages like "Error in Application", "There is an error" etc. Instead give specific messages like "Failed to update database. Please make sure the login id and password are correct."

21.  When displaying error messages, in addition to telling what is wrong, the message should also tell what should the user do to solve the problem. Instead of message like "Failed to update database.", suggest what should the user do: "Failed to update database. Please make sure the login id and password are correct."

22.  Show short and friendly message to the user. But log the actual error with all possible information. This will help a lot in diagnosing problems.

23.  Do not have more than one class in a single file.

24.  Have your own templates for each of the file types in Visual Studio. You can include your company name, copy right information etc in the template. You can view or edit the Visual Studio file templates in the folder C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\ItemTemplatesCache\CSharp\1033. (This folder has the templates for C#, but you can easily find the corresponding folders or any other language)

25.  Avoid having very large files. If a single file has more than 1000 lines of code, it is a good candidate for refactoring. Split them logically into two or more classes.

26.   Avoid public methods and properties, unless they really need to be accessed from outside the class. Use “internal” if they are accessed only within the same assembly.

27.   Avoid passing too many parameters to a method. If you have more than 4~5 parameters, it is a good candidate to define a class or structure.

28.   If you have a method returning a collection, return an empty collection instead of null, if you have no data to return. For example, if you have a method returning an ArrayList, always return a valid ArrayList. If you have no items to return, then return a valid ArrayList with 0 items. This will make it easy for the calling application to just check for the “count” rather than doing an additional check for “null”.

29.   Use the AssemblyInfo file to fill information like version number, description, company name, copyright notice etc.

30.   Logically organize all your files within appropriate folders. Use 2 level folder hierarchies. You can have up to 10 folders in the root folder and each folder can have up to 5 sub folders. If you have too many folders than cannot be accommodated with the above mentioned 2 level hierarchy, you may need re factoring into multiple assemblies.

16.  Make sure you have a good logging class which can be configured to log errors, warning or traces. If you configure to log errors, it should only log errors. But if you configure to log traces, it should record all (errors, warnings and trace). Your log class should be written such a way that in future you can change it easily to log to Windows Event Log, SQL Server, or Email to administrator or to a File etc without any change in any other part of the application. Use the log class extensively throughout the code to record errors, warning and even trace messages that can help you trouble shoot a problem.

17.  If you are opening database connections, sockets, file stream etc, always close them in the finally block. This will ensure that even if an exception occurs after opening the connection, it will be safely closed in the finally block.

18.  Declare variables as close as possible to where it is first used. Use one variable declaration per line.

19.  Use StringBuilder class instead of String when you have to manipulate string objects in a loop. The String object works in weird way in .NET. Each time you append a string, it is actually discarding the old string object and recreating a new object, which is a relatively expensive operations.

Consider the following example:

public string ComposeMessage (string[] lines)
{
   string message = String.Empty;

   for (int i = 0; i < lines.Length; i++)
   {
      message += lines [i];
   }

   return message;
}

In the above example, it may look like we are just appending to the string object ‘message’. But what is happening in reality is, the string object is discarded in each iteration and recreated and appending the line to it.

If your loop has several iterations, then it is a good idea to use StringBuilder class instead of String object.

See the example where the String object is replaced with StringBuilder.

public string ComposeMessage (string[] lines)
{
    StringBuilder message = new StringBuilder();

    for (int i = 0; i < lines.Length; i++)
    {
       message.Append( lines[i] );
    }

    return message.ToString();
}



1.     Always use multi layer (N-Tier) architecture.

2.    Never access database from the UI pages. Always have a data layer class which performs all the database related tasks. This will help you support or migrate to another database back end easily.

3.    Use try-catch in your data layer to catch all database exceptions. This exception handler should record all exceptions from the database. The details recorded should include the name of the command being executed, stored proc name, parameters, connection string used etc. After recording the exception, it could be re thrown so that another layer in the application can catch it and take appropriate action.

4.    Separate your application into multiple assemblies. Group all independent utility classes into a separate class library. All your database related files can be in another class library.


1.     Do not use session variables throughout the code. Use session variables only within the classes and expose methods to access the value stored in the session variables. A class can access the session using System.Web.HttpCOntext.Current.Session

2.     Do not store large objects in session. Storing large objects in session may consume lot of server memory depending on the number of users.

3.     Always use style sheet to control the look and feel of the pages. Never specify font name and font size in any of the pages. Use appropriate style class. This will help you to change the UI of your application easily in future. Also, if you like to support customizing the UI for each customer, it is just a matter of developing another style sheet for them


Good and meaningful comments make code more maintainable. However,

1.     Do not write comments for every line of code and every variable declared.

2.     Use // or /// for comments. Avoid using /* … */

3.     Write comments wherever required. But good readable code will require very less comments. If all variables and method names are meaningful, that would make the code very readable and will not need many comments.

4.     Do not write comments if the code is easily understandable without comment. The drawback of having lot of comments is, if you change the code and forget to change the comment, it will lead to more confusion.

5.     Fewer lines of comments will make the code more elegant. But if the code is not clean/readable and there are less comments, that is worse.

6.     If you have to use some complex or weird logic for any reason, document it very well with sufficient comments.

7.     If you initialize a numeric variable to a special number other than 0, -1 etc, document the reason for choosing that value.

8.     The bottom line is, write clean, readable code such a way that it doesn't need any comments to understand.

9.     Perform spelling check on comments and also make sure proper grammar and punctuation is used.


1.     Never do a 'catch exception and do nothing'. If you hide an exception, you will never know if the exception happened or not. Lot of developers uses this handy method to ignore non significant errors. You should always try to avoid exceptions by checking all the error conditions programmatically. In any case, catching an exception and doing nothing is not allowed. In the worst case, you should log the exception and proceed.

2.     In case of exceptions, give a friendly message to the user, but log the actual error with all possible details about the error, including the time it occurred, method and class name etc.

3.     Always catch only the specific exception, not generic exception.

Good:


       void ReadFromFile ( string fileName )
       {
              try
              {
                     // read from file.
              }
              catch (FileIOException ex)
              {
                     // log error.
                     //  re-throw exception depending on your case.
                     throw;
              }
       }

Not Good:


void ReadFromFile ( string fileName )
{
   try
   {
      // read from file.
   }
   catch (Exception ex)    
   {
      // Catching general exception is bad... we will never know whether
      // it was a file error or some other error.            
      // Here you are hiding an exception.
      // In this case no one will ever know that an exception happened.

      return "";           
   }
}
               

4.     No need to catch the general exception in all your methods. Leave it open and let the application crash. This will help you find most of the errors during development cycle. You can have an application level (thread level) error handler where you can handle all general exceptions. In case of an 'unexpected general error', this error handler should catch the exception and should log the error in addition to giving a friendly message to the user before closing the application, or allowing the user to 'ignore and proceed'.

5.     When you re throw an exception, use the throw statement without specifying the original exception. This way, the original call stack is preserved.

Good:

catch
{
       // do whatever you want to handle the exception

       throw;
}

Not Good:

catch (Exception ex)
{
       // do whatever you want to handle the exception

       throw ex;
}

6.     Do not write try-catch in all your methods. Use it only if there is a possibility that a specific exception may occur and it cannot be prevented by any other means. For example, if you want to insert a record if it does not already exists in database, you should try to select record using the key. Some developers try to insert a record without checking if it already exists. If an exception occurs, they will assume that the record already exists. This is strictly not allowed. You should always explicitly check for errors rather than waiting for exceptions to occur. On the other hand, you should always use exception handlers while you communicate with external systems like network, hardware devices etc. Such systems are subject to failure anytime and error checking is not usually reliable. In those cases, you should use exception handlers and try to recover from error.

7.     Do not write very large try-catch blocks. If required, write separate try-catch for each task you perform and enclose only the specific piece of code inside the try-catch. This will help you find which piece of code generated the exception and you can give specific error message to the user.


8.      Write your own custom exception classes if required in your application. Do not derive your custom exceptions from the base class SystemException. Instead, inherit from ApplicationException.